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Chapter: 18 -Problem: 18 >> Stars whose luminosity and period of variation are related are called a. Pulsars b. Cepheid variables c. Main-sequence starsd. Giants
Answer Preview: b Cepheid Variables These stars are used …

, Chapter: 14 -Problem: 30 >> A wind in the northern hemisphere starts to blow toward the equator. Toward what direction is the wind deflected by the coriolis effect? What about a wind in the southern hemisphere also starting to blow toward the equator?
Answer Preview: Towar…

, Chapter: 11 -Problem: 36 >> The net reaction between a strong acid and a strong base is a. H2O ? H+ + OHb. H+ + OH- ? H2O c. H2O + H2O ? H3O+ + OHd. H+ + H2O ? H3O+
Answer Preview: Option B H OH H2O When strong acid reacts wi…

, Chapter: 6 -Problem: 52 >> In an older type of TV picture tube, a beam of electrons perpendicular to a fluorescent screen scans across the screen, which glows where the electrons strike it. When you face the screen, in what direction is the magnetic field of the electron beam?
Answer Preview: The magnetic fie…

, Chapter: 3 -Problem: 23 >> Car A has a mass of 1000 kg and is moving at 60 km/h. Car B has a mass of 2000 kg and is moving at 30 km/h. The kinetic energy of car A is a. half that of car B b. equal to that of car B c. twice that of car B d. 4 times that of car B
Answer Preview: Mass m A 1000 kg Velocity v A 60 km h 60 5 18 16 66 …

, Chapter: 18 -Problem: 15 >> The sun’s energy comes from a. Nuclear fission b. Radioactivity c. The conversion of hydrogen to helium d. The conversion of helium to hydrogen
Answer Preview: Nuclear fission reactions occur when large radioactive atoms …

, Chapter: 11 -Problem: 20 >> What is the difference between a molecular ion and a polar molecule?
Answer Preview: A molecular ion is a molecule that has gained or lost one or more …

, Chapter: 11 -Problem: 18 >> The most strongly polar liquid of the following is a. water b. alcohol c. a detergent d. gasoline
Answer Preview: Water is a polar liquid as it contains polar bonds in it…

, Chapter: 6 -Problem: 36 >> Wire A has a potential difference of 50 V across it and carries a current of 2 A. Wire B has a potential difference of 100 V across it and also carries a current of 2 A. Compare the resistances, rates of flow of charge, and rates of flow of energy in the two wires.
Answer Preview: a for wire A an…

, Chapter: 2 -Problem: 45 >> The brakes of a 1200-kg car exert a force of 4 kN. How long will it take for them to slow the car to a stop from an initial speed of 24 m/s?
Answer Preview: Mass 1200 kg Force 4kN 4000 N Initial …

, Chapter: 18 -Problem: 17 >> If we know both the luminosity and brightness of a star, we can find its a. massb. temperature c. distanced. age
Answer Preview: Option c We can find th…

, Chapter: 12 -Problem: 54 >> When an electric current is passed through a solution of copper chloride, what substance is liberated at the positive electrode? At the negative electrode?
Answer Preview: Chlo…

, Chapter: 11 -Problem: 20 >> Nonpolar substances usually dissolve most readily in a. polar liquids b. nonpolar liquids c. acids d. bases
Answer Preview: Vander wall forces exist between nonpolar components and th…

, Chapter: 6 -Problem: 22 >> Why do you think bending a wire does not affect its electrical resistance, even though a bent pipe offers more resistance to the flow of water than a straight one?
Answer Preview: Electrons are sma…

, Chapter: 3 -Problem: 47 >> When the kinetic energy of an object is doubled, what happens to its momentum?
Answer Preview: Let s assume Mass M Velocity V Initial Kinetic Energy K initial m…

, Chapter: 18 -Problem: 14 >> The sun does not a. have a magnetic field b. have a solid core c. revolve about an axis d. consist largely of ions
Answer Preview: The Sun is a typical sphere of hot gas and most of this ga…

, Chapter: 14 -Problem: 28 >> What is the basic cause of winds?
Answer Preview: Uneven …

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, Chapter: 5 -Problem: 82 >> How much heat is given off when 1 kg of steam at 100°C condenses and cools to water at 20°C?
Answer Preview: The heat of vaporization of …

, Chapter: 4 -Problem: 1 >> In 2100 the number of people in the world is predicted to reach at least a. 1 billion b. 2.5 billion c. 7 billion d. 9.6 billion
Answer Preview: 9 6 Billion is the min…

, Chapter: 18 -Problem: 7 >> Suppose a star had a cool interior surrounded by a hot atmosphere. What kind of spectrum would it have?
Answer Preview: If a star has a cool interior surrounded by a hot gaseou…

, Chapter: 13 -Problem: 4 >> How can the different alkanes in petroleum be separated? What property of the alkanes makes this procedure possible?
Answer Preview: Fractional distill…

, Chapter: 11 -Problem: 30 >> The reason pure acids in the liquid state are not dissociated is that their chemical bonds are a. ionic b. covalent c. metallic d. van der Waals
Answer Preview: Pure acids do not have ions in the liq…

, Chapter: 3 -Problem: 55 >> The 176-g head of a golf club is moving at 45 m/s when it strikes a 46-g golf ball and sends it off at 65 m/s. Find the final speed of the clubhead after the impact, assuming that the mass of the club’s shaft can be neglected.
Answer Preview: This question can be solved by conse…

, Chapter: 18 -Problem: 30 >> A typical white dwarf star is about the size of a. A large building b. The moon c. The earthd. Jupiter
Answer Preview: A typical white dwarf is abou…

, Chapter: 15 -Problem: 24 >> How could you distinguish (a) chert from obsidian;(b) conglomerate from gneiss; (c) quartz from calcite?
Answer Preview: a Obsidian is black and shiny while chert may be any …

, Chapter: 11 -Problem: 29 >> Acids invariably contain a. hydrogen b. oxygen c. chlorine d. water
Answer Preview: Acids are those compounds th…

, Chapter: 2 -Problem: 44 >> A car rounds a curve at 20 km/h. If it rounds the curve at 40 km/h, its tendency to overturn is a. halved b. doubled c. tripled d. quadrupled
Answer Preview: d quadrupled When an object moves in a circular path it ex…

, Chapter: 18 -Problem: 21 >> Intense auroral activity occurs in the earth’s upper atmosphere about 30 h after a solar storm. What is the average speed of the ions emitted during the storm?
Answer Preview: We know that the distance between the earth and the sun is 1 5 10 11 …

, Chapter: 14 -Problem: 24 >> If the earth’s axis were tilted more than its present 23.5°, in what way, if any, would the seasons be affected?
Answer Preview: The seasons would be more …

, Chapter: 10 -Problem: 41 >> What is the charge on alkali metal ions? On halogen ions? On oxygen ions?
Answer Preview: The charge on alkali …

, Chapter: 3 -Problem: 20 >> The work a 300-W electric grinder can do in 5.0 min is a. 1 kJ b. 1.5 kJ c. 25 kJ d. 90 kJ
Answer Preview: Step 1 Power Formula set up P Work time Step 2 Inlet …

, Chapter: 3 -Problem: 38 >> A ramp 20 m long slopes down 1.2 m to the edge of a lake. A force of 300 N is needed to pull a boat on a trailer at constant speed up the ramp when they are clear of the water. If friction is negligible, what is the combined mass of boat and trailer?
Answer Preview: Solution. We can calculate the total mass of boat …

, Chapter: 18 -Problem: 19 >> What aspect of sunspots changes during a sunspot cycle?
Answer Preview: a sunspot cycle is 11 years old it is half of a longer 22 year cycle of solar a…

, Chapter: 15 -Problem: 22 >> Distinguish between the foliation of a metamorphic rock and the stratification of a sedimentary rock.
Answer Preview: Metamorphic rocks are foliated because under heat and pressure their mineral grains grow in lon…

, Chapter: 11 -Problem: 53 >> How could you prepare the weak acid H2S from the salt Na2S (sodium sulfide)?
Answer Preview: In the case of alkaline Na 2 S reacted wi…

, Chapter: 3 -Problem: 7 >> The acceleration of gravity on the surface of Mars is 3.7 m/s2. If an astronaut in a space suit can jump upward 20 cm on the earth’s surface, how high could he jump on the surface of Mars?
Answer Preview: At the height point of jump the velocity of astronaut will be ze…

, Chapter: 2 -Problem: 30 >> A ball dropped from the roof of a building takes 4 s to reach the street. How high is the building?
Answer Preview: Given, Initial velocity = u = 0 time tak…

, Chapter: 18 -Problem: 41 >> Why must a star have a certain minimum mass in order to radiate?
Answer Preview: Because of the thermonuclear reactions in star core which release enormous amounts of …

, Chapter: 12 -Problem: 4 >> For a given amount of energy to be used for its propulsion, a spacecraft must have much larger tanks than an airplane. Why?
Answer Preview: The airplane uses oxygen from …

, Chapter: 6 -Problem: 18 >> Magnetic field lines provide a convenient way to visualize a magnetic field. Which of the following statements is not true? a. The path followed by an iron particle released near a magnet corresponds to a field line. b. The path followed by an electric charge released near a magnet corresponds to a field line. c. A compass needle in a magnetic field turns until it is parallel to the field lines ar
Answer Preview: The path of a free electric charge represe…

, Chapter: 11 -Problem: 10 >> A property of metals that is not due to the electron sea in them is their ability to a. conduct electricity b. conduct heat c. reflect light d. form oxides
Answer Preview: In metals the valence electrons are free to move throughout the solid …

, Chapter: 3 -Problem: 30 >> A 1-kg ball is thrown in the air. When it is 10 m above the ground, its speed is 3 m/s. At this time most of the ball’s total energy is in the form ofa. kinetic energy b. potential energy relative to the ground c. rest energy d. momentum
Answer Preview: Given mass of the ball 1kg Height of the ball from earth at given instant 10m velocity of the …

, Chapter: 3 -Problem: 58 >> A 1000-kg car moving east at 80 km/h collides head-on with a 1500-kg car moving west at 40 km/h, and the two cars stick together. (a) Which way does the wreckage move and with what initial speed? (b) How much KE is lost in the collision?
Answer Preview: Solution. a). - the wreckage moves to the west at an initial velocity of (80+40)/2 …

, Chapter: 18 -Problem: 3 >> Why do stars seem to twinkle?
Answer Preview: The stars twinkle in the night sky because of the effect…

, Chapter: 12 -Problem: 40 >> To what extent does the time needed for a strong acid to neutralize a strong base in solution depend on temperature?
Answer Preview: The time is virtua…

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, Chapter: 11 -Problem: 9 >> Van der Waals forces are strong enough to hold inert gas atoms together to form liquids at low temperatures, but these forces do not lead to inert gas molecules at higher temperatures. Why not?
Answer Preview: At high temperatures the inert gases are in gaseous form In …

, Chapter: 4 -Problem: 1 >> What are the three main factors that will require changes in today’s patterns of energy production and consumption?
Answer Preview: There are three main factors that will require changes in today s pattern of energy production and …

, Chapter: 3 -Problem: 20 >> Is the work needed to bring a car’s speed from 0 to 10 km/h less than, equal to, or more than the work needed to bring its speed from 10 to 20 km/h? If the amounts of work are different, what is the ratio between them?
Answer Preview: Solution. We can see that bringing the speed from zero to 10 km/h is much easie…

, Chapter: 2 -Problem: 31 >> A ball is thrown downward at 12 m/s. What is its speed 1.0 s later?
Answer Preview: step1 the given problem can be solved using ist equation of motio…

, Chapter: 18 -Problem: 12 >> Solar storms may affect which one(s) of these? a. The earth’s magnetic field b. Electric transmission lines c. Shortwave radio reception d. Satellite electronics
Answer Preview: Ans Firstly there is a huge chance that the solar storm can affect all the options mentioned in the question i e earth s magnetic field electric transmission lines short wave radio reception satellite …

, Chapter: 14 -Problem: 32 >> Where in the atmosphere do the jet streams occur? What is their general direction?
Answer Preview: The jet streams …

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, Chapter: 2 -Problem: 59 >> A person stands on a scale in an elevator. When the elevator is at rest, the scale reads 700 N. When the elevator starts to move, the scale reads 600 N.(a) Is the elevator going up or down?(b) Is it accelerated? If so, what is the acceleration?
Answer Preview: A person stands on a scale in an elevator In the first case elevat…

, Chapter: 3 -Problem: 12 >> An escalator 14 m long is carrying a 70-kg person from one floor to another 8 m higher. The escalator has a speed of 1.0 m/s. (a) How much work does the escalator do in carrying the person to the top? (b) What is its power output while doing so?
Answer Preview: a. W = mgh = …

, Chapter: 1 -Problem: 33 >> How many microphones are there in a megaphone?
Answer Preview: 1megaphone 10 6 …

, Chapter: 17 -Problem: 43 >> Saturn’s satellite Titan has an atmosphere. Do any of the other planetary satellites also have atmospheres?
Answer Preview: Saturns satellite Titan has mostly Earth like atmosphere It is the second large…

, Chapter: 11 -Problem: 44 >> What salt is formed when a solution of calcium hydroxide is neutralized by phosphoric acid, H3PO4? Give the equation of the process.
Answer Preview: Ca 3 PO 4 …

, Chapter: 5 -Problem: 41 >> A wooden block is submerged in a tank of water and pressed down against the bottom of the tank so that there is no water underneath it. The block is released. Will it rise to the surface or stay where it is?
Answer Preview: Theoretically speaking No the block will not rise u…

, Chapter: 11 -Problem: 45 >> What salt is formed when a solution of calcium hydroxide is neutralized by hydrochloric acid? Give the equation of the process.
Answer Preview: Reaction is Ca OH 2 s 2HCl …

, Chapter: 5 -Problem: 84 >> Many power stations get rid of their waste heat by using it to boil water and allowing the resulting steam to escape into the atmosphere via a cooling tower. How much water would a power station need per second to dispose of 1000 MW of waste heat? Consider only the vaporization of the water; the heat used to raise the water to the boiling point is much less.
Answer Preview: 1000 …

, Chapter: 3 -Problem: 41 >> An 800-kg car coasts down a hill 40 m high with its engine off and the driver’s foot pressing on the brake pedal. At the top of the hill the car’s speed is 6 m/s and at the bottom it is 20 m/s. How much energy was converted into heat on the way down?
Answer Preview: Solution Let the energy loss in the form of heat is H Apply …

, Chapter: 19 -Problem: 38 >> In what way or ways, if any, is the sun an unusual star?
Answer Preview: Solution; The sun is by far the largest star in our solar system. It is approximately 2 2 million …

, Chapter: 2 -Problem: 25 >> A stone is thrown horizontally from a cliff and another, identical stone is dropped from there at the same time. Do the stones reach the ground at the same time? How do their speeds compare when they reach the ground? Their accelerations?
Answer Preview: Time of Flight Both the stones will reach at the same time Speeds The speeds …

, Chapter: 17 -Problem: 61 >> The moon’s maria are dark, relatively smooth regions conspicuous even to the naked eye. What is their nature?
Answer Preview: Moon that always faces Earth Maria are the largest topographic features …

, Chapter: 13 -Problem: 48 >> The ultimate source of the energy in food is the energy liberated when hydrogen is converted to helium in thermonuclear reactions in the sun. Trace this energy from the sun to the food you eat.
Answer Preview: The energy produced in the sun is given off as …

, Chapter: 5 -Problem: 35 >> A 1200-lb car is equally supported by its four tires, which are inflated to a pressure of 2 bar. What area of each tire is in contact with the road?
Answer Preview: right in this problem We know the pressure and your car is 2 5 times to five Pascal s Tha…

, Chapter: 11 -Problem: 23 >> You have a solution that contains Cl- ions and another that contains NO 3- ions. How would adding a solution that contains Ag+ ions to these solutions enable you to tell which is which?
Answer Preview: Adding a solution that contains Ag ions to a solution that contains Cl ions will produce a colo…

, Chapter: 7 -Problem: 54 >> The candle of Exercise 53 is 15 cm from the lens. Answer the same questions for this situation.
Answer Preview: No image is …

, Chapter: 2 -Problem: 53 >> A person weighs 85 N on the surface of the moon and 490 N on the surface of the earth. What is the acceleration of gravity on the surface of the moon?
Answer Preview: The weight of person on earth is given as Mg 490 N where …

, Chapter: 2 -Problem: 58 >> A person in an elevator suspends a 1-kg mass from a spring balance. What is the nature of the elevator’s motion when the balance reads 9.0 N? 9.8 N? 10.0 N?
Answer Preview: The elevator's motion is linear when the balance reads 9 0 N. T…

, Chapter: 2 -Problem: 43 >> The radius of the circle in which an object is moving at constant speed is doubled. The required centripetal force is a. one-quarter as great as before b. one-half as great as before c. twice as great as before d. 4 times as great as before
Answer Preview: Ans b one half as great as before Centripetal force is the force that is n…

, Chapter: 17 -Problem: 42 >> The moon’s surface is a. Perfectly smooth b. Irregular but relatively smoother than the earth’s surface c. About as irregular as the earth’s surface d. Much more irregular than the earth’s surface
Answer Preview: No planet has a perfectly smooth surface Hence option …

, Chapter: 10 -Problem: 54 >> When chlorine gas is bubbled through a solution of sodium hydroxide (NaOH), the products are sodium hypochlorite (NaOCl), sodium chloride, and another substance. What is the other substance? Give the equation of the process.
Answer Preview: H 2 O …

, Chapter: 5 -Problem: 65 >> At absolute zero, a sample of an ideal gas would have zero volume. Why would this not be true of an actual gas at absolute zero?
Answer Preview: In ideal gas there is no collision between the mol…

, Chapter: 11 -Problem: 32 >> A common strong acid is a. acetic acid b. boric acid c. nitric acid d. citric acid
Answer Preview: Answer Option c is correct Common strong …

, Chapter: 6 -Problem: 4 >> Why does the production of electricity by friction always yield equal amounts of positive and negative charge?
Answer Preview: The production of electricity by friction involves the removal of electrons from on…

, Chapter: 3 -Problem: 27 >> Why does a nail become hot when it is hammered into a piece of wood?
Answer Preview: A nail becomes warm when hammered into a wood because every time th…

, Chapter: 19 -Problem: 34 >> To what event in the history of the universe can the cosmic microwave background radiation be traced? Was the radiation always in the form of microwaves? If not, what happened to change the wavelengths of the original radiation?
Answer Preview: Solution; The event that changed the wavelengths of the original radiation wa…

, Chapter: 1 -Problem: 21 >> What is the difference between spring and neap tides? Under what circumstances does each occur?
Answer Preview: Tides occur due to three reasons 1 Gravitational pull of Moon 2 Gravitational pull of Sun 3 Earth s …

, Chapter: 18 -Problem: 6 >> The sun’s atmosphere a. Extends out into the solar system b. Consists mainly of oxygen and nitrogen c. Consists of burning hydrogen d. Is relatively cool
Answer Preview: Answer c consists of burning hydrogen Explanation for each option A It does not exte…

, Chapter: 12 -Problem: 52 >> In the refining of iron the iron(III) oxide, Fe2O3, in iron ore is reduced by carbon (in the form of coke) to yield metallic iron and carbon dioxide. Write the balanced equation of the process.
Answer Preview: 2Fe …

, Chapter: 6 -Problem: 7 >> Find the total charge of 1 g of protons.
Answer Preview: Given data Mass of Proton m p 1 67x10 17 kg Charge of Prot…

, Chapter: 12 -Problem: 9 >> When a catalyst promotes a chemical reaction, it usually does so by a. providing energy b. providing electrons c. producing activated molecules d. becoming permanently altered
Answer Preview: A substance that changes the rate of a chemical reac…

, Chapter: 15 -Problem: 62 >> What factors determine the viscosity of a magma? What kinds of landscapes are produced by volcanoes whose lavas have relatively high and relatively low viscosities?
Answer Preview: a The higher the content of silica and the lower the cont…

, Chapter: 2 -Problem: 73 >> A 40-kg crate is lying on the flat floor of a truck moving at 15 m/s. A force of 150 N is needed to slide the crate against the friction between the bottom of the crate and the floor. What is the minimum radius of a turn the station wagon can make if the box is not to slip?
Answer Preview: Given Mass of the crate 40kg velocity of truck 15m s For…

, Chapter: 2 -Problem: 50 >> Before picking up the passengers, the driver of the car of Exercise 49 shifts into neutral when the car is moving at 80 km/h and finds that its speed has dropped to 65 km/h after 10 s. What was the average drag force acting on the car?
Answer Preview: Drag is a force acting opposite to the relative motion of any object moving. …

, Chapter: 1 -Problem: 17 >> The average distance from the earth to the sun is called the astronomical unit (AU). If an asteroid is 4 AU from the sun and its period of revolution around the sun is 8 years, does it obey Kepler’s third law?
Answer Preview: Consider the orbit of asteroid is circular Let us assume it obeys kepler s third law T 2 …

, Chapter: 18 -Problem: 2 >> Most stars have hot interiors surrounded by relatively cool atmospheres. The spectrum of such a star consists of a. white lines against a dark background b. colored lines against a dark background c. dark lines against a white background d. dark lines against a colored background
Answer Preview: An electromagnetic spectrum of dark bands on a continuous c…

, Chapter: 12 -Problem: 16 >> Find the mass of 30 mol of sulfuric acid, H2SO4.
Answer Preview: The formula mass of …

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, Chapter: 11 -Problem: 28 >> The ions usually responsible for “hard” water are a. H+ and OH-. b. Na+ and Cl-. c. Ca2+ and Mg2+ d. SO 42 - and NO 3 -
Answer Preview: Option c is correct Common captions found in hard water …

, Chapter: 7 -Problem: 2 >> Does increasing the frequency of a wave also increase its wavelength? If not, how are these quantities related?
Answer Preview: Increasin…

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, Chapter: 2 -Problem: 76 >> Some people believe that aliens from elsewhere in the universe visit the earth in spacecraft that travel faster than jet airplanes and can turn in their own lengths. Calculate the centripetal force on a 100-kg alien in a spacecraft moving at 500 m/s (1120 mi/h) while it is making a turn of radius 30 m. How many times the weight of the alien is this force? Do you think such stories can be believed?
Answer Preview: Solution and explanation. According to Newton's Third Law of Motion, "for every action, there is …

, Chapter: 2 -Problem: 7 >> Is it correct to say that scalar quantities are abstract, idealized quantities with no precise counterparts in the physical world, whereas vector quantities properly represent reality because they take directions into account?
Answer Preview: All quantities in the physical world need not be represented b…

, Chapter: 18 -Problem: 17 >> Suppose the earth’s magnetic field were to disappear. What effect would this have on the aurora?
Answer Preview: If the magnetic field disappeared A larger number of charged solar particles would …

, Chapter: 1 -Problem: 34 >> Use the proper number of significant figures to express the values of a. 47.2 + 9.11 - 14 b. (3.58 × 102)(2.1 × 103) c.  Transcribed Image Text: 7.8 x 103 3.21 x 10-2 + 5.4 × 104
Answer Preview: 42 7…

, Chapter: 5 -Problem: 87 >> Water at 50°C can be obtained by mixing together which one or more of the following? Which of the others would have final temperatures higher than 50°C and which lower than 50°C?a. 1 kg of ice at 0°C and 1 kg of steam at 100°C b. 1 kg of ice at 0°C and 1 kg of water at 100°C c. 1 kg of water at 0°C and 1 kg of steam at 100°C d. 1 kg of water at 0°C and 1 kg of water at 100°C
Answer Preview: Hot water at 80C and cold water at 10C Mixing hot water at 80C and cold water at 10C would re…

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, Chapter: 7 -Problem: 52 >> If the screen is moved farther from a slide projector, how should the projector’s lens be moved to restore the image to a sharp focus?
Answer Preview: The lens …

, Chapter: 3 -Problem: 67 >> Why is it impossible for an object to move faster than the speed of light?
Answer Preview: Particles that have mass require energy to accelera…

, Chapter: 2 -Problem: 26 >> A ship travels 200 km to the south and then 400 km to the west. The ship’s displacement from its starting point isa. 200 km b. 400 km c. 450 km d. 600 km
Answer Preview: Distance travelled by ship in south direction 200km Distance tr…

, Chapter: 18 -Problem: 35 >> Must a star be spherical?
Answer Preview: A star is never spherical because of the centrifugal force acting on it due to …

, Chapter: 15 -Problem: 4 >> What mineral is most abundant in the earth’s crust? Does it make up more or less than half of the mass of the crust?
Answer Preview: Feld…

, Chapter: 5 -Problem: 25 >> A frictionless heat engine can be 100 percent efficient only if its exhaust temperature is a. equal to its input temperature b. less than its input temperature c. 0°C d. 0 K
Answer Preview: Efficiency of an Ideal Heat engine is give…

, Chapter: 11 -Problem: 35 >> Would you expect HBr to be a weak or strong acid? Why?
Answer Preview: HBr would be considered str…

, Chapter: 8 -Problem: 32 >> Why is the 2566 Fe nucleus the most stable (that is, the most difficult to break apart) nucleus?
Answer Preview: This nucleu…

, Chapter: 3 -Problem: 33 >> A skier is sliding downhill at 8 m/s when she reaches an icy patch on which her skis move freely with negligible friction. The difference in altitude between the top of the icy patch and its bottom is 10 m. What is the speed of the skier at the bottom of the icy patch? Do you have to know her mass?
Answer Preview: Solution Given Initial speed v o 8 m s difference i…

, Chapter: 2 -Problem: 22 >> An astronaut inside an orbiting satellite feels weightless because a. He or she is wearing a space suit b. The satellite is falling toward the earth just as fast as the astronaut is, so there is no upward reaction force on him or her c. There is no gravitational pull from the earth so far away d. The sun’s gravitational pull balances out the earth’s gravitational pull
Answer Preview: option B is the correct answer An astronaut feels weightless in the satellite because both the ast…

, Chapter: 18 -Problem: 25 >> Stars belonging to the main sequence a. Have the same mass b. Have the same temperature c. Radiate at steady rates d. Fluctuate markedly in brightness
Answer Preview: In the beginning of the stellar life cycle the mass of a sta…

, Chapter: 1 -Problem: 28 >> The diameter of an atom is roughly 104 times the diameter of its nucleus. If the nucleus of an atom were 1 mm across, how many feet across would the atom be?
Answer Preview: 1 mm 10 3 m …

, Chapter: 6 -Problem: 14 >> The electric energy lost when a current passes through a resistance a. becomes magnetic energy b. becomes potential energy c. potential difference ohm d. power watt
Answer Preview: The resistor is an electronic device that opposes the flow of cur…

, Chapter: 12 -Problem: 9 >> How many moles of propane, C3H8, can be prepared from 1 mol of carbon? From 1 mol of hydrogen?
Answer Preview: A propane molecule contains three carbon atoms That is one mole of propa…

, Chapter: 7 -Problem: 30 >> Radio waves of very long wavelength can penetrate farther into seawater than those of shorter wavelength. The U.S. Navy communicates with submerged submarines using 76-Hz radio waves. What is their wavelength in air?
Answer Preview: c …

, Chapter: 2 -Problem: 67 >> When a 5-kg rifle is fired, the 9-g bullet is given an acceleration of 30 km/s while it is in the barrel.(a) How much force acts on the bullet?(b) Does any force act on the rifle? If so, how much and in what direction?
Answer Preview: Given weight of rifle 5kg weight o…

, Chapter: 1 -Problem: 5 >> According to the physicist Richard Feynman, “Science is the culture of doubt.” Does this mean that science is an unreliable guide to the natural world?
Answer Preview: Richard Feynman s comment does not mean that science is an unreliable guide He is only trying to con…

, Chapter: 18 -Problem: 7 >> Auroras are caused by a. streams of colored gases from the sun b. streams of charged particles from the sun c. comets d. micrometeorites
Answer Preview: Auroras are caused by streams of charged particles from the sun which enter the Earths a…

, Chapter: 13 -Problem: 34 >> Which of the following (a) dissolve in water,(b) are acids, (c) react with ethyl alcohol to give esters, (d) react with acetic acid to give esters?C2H5COOH C3H8 C2H4 C2H5OH HCl C3H5(OH)3
Answer Preview: a C 2 H 5 COOH C 2 H …

, Chapter: 6 -Problem: 20 >> A moving electric charge produces a. only an electric field b. only a magnetic field c. both an electric and a magnetic field d. any of these, depending on its speed
Answer Preview: There should be a motion in the electric charge due to which both magnetic and elec…

, Chapter: 11 -Problem: 3 >> Are ionic or covalent crystals more common?
Answer Preview: We know that the atoms of ionic crystals are held together by ionic bonds These bond…

, Chapter: 6 -Problem: 48 >> The magnetic poles of the earth are called geomagnetic poles. Is the north geomagnetic pole a north magnetic pole or a south magnetic pole?
Answer Preview: The north magnetic pole of a compass points nort…

, Chapter: 2 -Problem: 83 >> Is the sun’s gravitational pull on the earth the same at all seasons of the year? Explain.
Answer Preview: No the earth gravitational pull on earth is different on different seasons Because we know th…

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, Chapter: 6 -Problem: 2 >> A positive electric charge a. attracts other positive charges b. repels other positive charges c. does not interact with other positive charges but only with negative ones d. consists of an excess of electrons
Answer Preview: According to the characteristic of electric …

, Chapter: 12 -Problem: 11 >> Reaction rates increase with temperature primarily because a. dissociation into ions is more complete b. more collisions occur between the molecules involved c. more activated molecules are formed d. equilibrium does not occur at high temperatures
Answer Preview: The answer is b More collisions occur between t…

, Chapter: 8 -Problem: 48 >> (a) Could a gamma ray just energetic enough to materialize into a proton-antiproton pair alternatively materialize into a neutron-antineutron pair?(b) Could a gamma ray energetic enough to materialize into a neutron-antineutron pair alternatively materialize into a proton-antiproton pair? Explain.
Answer Preview: A neutron has …

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, Chapter: 18 -Problem: 31 >> When the hydrogen supply in a typical main-sequence star begins to run out, other nuclear reactions occur and the star becomes a a. Giant b. White dwarf c. Supernovad. Neutron star
Answer Preview: a Giant When the hydrogen supply begins to run out nuclear reactions can no longer conti…

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, Chapter: 11 -Problem: 15 >> A solid is dissolved in a liquid. When the temperature of the solution is increased, the solubility of the solid a. increases b. decreases c. remains the same d. does any of these, depending upon the nature of the solution
Answer Preview: Solid material dissolves faster with increased temperature Since the increased tempe…

, Chapter: 6 -Problem: 34 >> Heavy users of electric power, such as large electric stoves and clothes dryers, are sometimes designed to operate on 240 V rather than 120 V. What advantage do you think the higher voltage has in these applications?
Answer Preview: Since a higher voltage means less c…

, Chapter: 3 -Problem: 34 >> The smallest part of the total energy of the ball of Multiple Choice 30 is a. kinetic energy b. potential energy relative to the ground c. rest energy d. momentum
Answer Preview: The smallest part of the total energy of the ball is rest energy R…

, Chapter: 18 -Problem: 23 >> What aspect of the formation of helium from hydrogen results in the evolution of energy?
Answer Preview: This process is called nuclear fusion This process occurs in the core o…

, Chapter: 6 -Problem: 19 >> How far apart are two charges of +1 × 10?8 C that repel each other with a force of 0.1 N?
Answer Preview: According to question given q 1 1 x 10 8 C F 0 1N q 2 1x10 8 C Concept the fo…

, Chapter: 12 -Problem: 7 >> If a given reaction is exothermic, the reverse reaction a. is exothermic b. is endothermicc. may involve no energy change d. any of these, depending on the reaction
Answer Preview: If the forward reaction is exothermic the reverse re…

, Chapter: 6 -Problem: 16 >> Two small spheres are given identical positive charges. When they are 1 cm apart, the repulsive force acting on each of them is 0.002 N. What would the force be if (a) The distance is increased to 3 cm?(b) One charge is doubled?(c) Both charges are tripled?(d) One charge is doubled and the distance is increased to 2 cm?
Answer Preview: a 0 0002…

, Chapter: 3 -Problem: 35 >> The lightest particle in an atom is an electron, whose rest mass is 9.1 × 10-31 kg. The energy equivalent of this mass is approximatelya. 10-13 Jb. 10-15 Jc. 3 × 10-23 Jd. 10-47 J
Answer Preview: we know that E mc 2 …

, Chapter: 18 -Problem: 37 >> Is it possible for an object with the mass and composition of the sun to exist without radiating energy?
Answer Preview: No Based on the Stefan Boltzmann Law All the objects with a temper…

, Chapter: 6 -Problem: 12 >> Match each of the electrical qualities listed below with the appropriate unit from the list on the right:a. resistance ..................... volt b. current ............................ ampere c. potential difference ...... ohm d. power ............................ watt
Answer Preview: Correct match a r…

, Chapter: 12 -Problem: 13 >> Find the mass of 10 mol of uranium, U. How many atoms are present in such a sample?
Answer Preview: Since mass of one mol of uranium isotope uranium 238 23…

, Chapter: 7 -Problem: 60 >> When a beam of white light passes perpendicularly through a flat pane of glass, it is not dispersed into a spectrum. Why not?
Answer Preview: Light that is perpendi…

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, Chapter: 18 -Problem: 32 >> A star like the sun eventually becomes a a. Black hole b. White dwarf c. Supernovad. Neutron star
Answer Preview: The sun is a main sequence star falling in the G category means it is an average size star …

, Chapter: 6 -Problem: 17 >> The force on an electron that moves in a curved path must be a. gravitational b. electrical c. magnetic d. one or more of these
Answer Preview: According to Coulomb s law the electrostatic force experienced by …

, Chapter: 12 -Problem: 3 >> What role does air play in combustion?
Answer Preview: combustion is high temperature exothermi…

, Chapter: 2 -Problem: 89 >> An airplane makes a vertical circle in which it is upside down at the top of the loop. Will the passengers fall out of their seats if there is no belt to hold them in place?
Answer Preview: When body is at top position So If minimum velocity …

, Chapter: 18 -Problem: 29 >> Which varies more, the masses of the stars or their sizes?
Answer Preview: The stars varies more by their sizes not …

, Chapter: 5 -Problem: 89 >> The oceans contain an immense amount of heat energy. Why can a submarine not make use of this energy for propulsion?
Answer Preview: In order to make use of the heat energy from the ocean submarines …

, Chapter: 11 -Problem: 8 >> Ice is an example of a. a covalent solid b. an ionic solid c. a metallic solid d. a molecular solid
Answer Preview: Ice is an example …

, Chapter: 3 -Problem: 29 >> A person uses a force of 300 N to pry up one end of a 120-kg box using a lever 2.4 m long. The distance from the end of the box to the fulcrum is a. 40 cm b. 49 cm c. 81 cm d. 171 cm
Answer Preview: Let ab be a lever of length 2 4m C be its fulcrum Let 120 kg weight put at end b at a distance …

, Chapter: 18 -Problem: 27 >> The greater the mass of a main-sequence star, the a. Younger it is b. Longer it will remain part of the main sequence c. Less hydrogen it contains d. Hotter it is
Answer Preview: Greaten mass means m…

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, Chapter: 10 -Problem: 57 >> Aluminum reacts with gaseous chlorine to give aluminum chloride.
Answer Preview: The equation for the reaction can be written in words as Aluminum gaseous chlorine aluminum chlorid…

, Chapter: 3 -Problem: 53 >> A 30-kg girl who is running at 3 m/s jumps on a stationary 10-kg sled on a frozen lake. How fast does the sled with the girl on it then move?
Answer Preview: Let m mass of girl 30kg M mass of sled 10kg u1 velocity of girl befo…

, Chapter: 18 -Problem: 34 >> A star that explodes as a supernova a. Has a mass much greater than that of the sunb. Has a mass much smaller than that of the sunc. Has a mass about equal to that of the sund. May have any mass
Answer Preview: a Has a mass much greater than that of …

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, Chapter: 11 -Problem: 27 >> The average salinity of seawater is about a. 0.1 percent b. 1.5 percent c. 3.5 percent d. 10 percent
Answer Preview: The total salinity or salt content p…

, Chapter: 3 -Problem: 27 >> The highest MA that can be obtained by a system of two pulleys is a. 2 b. 3 c. 4 d. 5
Answer Preview: Mechanical advantage the ratio betw…

, Chapter: 18 -Problem: 20 >> If we know the surface temperature and luminosity of a star, we can find its a. Mass b. Size c. Aged. Distance
Answer Preview: The luminosity L of a star the total energy produced by th…

, Chapter: 6 -Problem: 21 >> The magnetic field of a bar magnet resembles most closely the magnetic field of a. a straight wire carrying a direct current b. a straight wire carrying an alternating current c. a wire loop carrying a direct current d. a wire loop carrying an alternating current
Answer Preview: The electric and magnetic field is produced in a wire loop with an iron core whe…

, Chapter: 2 -Problem: 51 >> Consider the statement: Sara weighs 55 kg. What is wrong with the statement? Give two ways to correct it.
Answer Preview: Weight is a force and kilogram is the unit of mass …

, Chapter: 18 -Problem: 9 >> Suppose you examine the spectra of two stars receding from the earth and find that the lines in one are displaced farther toward the red end than those in the other. What conclusion can you draw?
Answer Preview: According to the Doppler Effect in stellar spectra a star moving toward the earth has a …

, Chapter: 5 -Problem: 35 >> When 1 kg of steam at 200°C loses 3 MJ of heat, the result is a. ice b. water and ice c. water d. water and steam
Answer Preview: According to the question 1 kg of steam at 200C loses 3 MJ of heat We have to find the components of …

, Chapter: 11 -Problem: 13 >> A saturated solution is a solution that a. contains the maximum amount of solute b. contains the maximum amount of solvent c. is in the process of crystallizing d. contains polar molecules
Answer Preview: A saturated solution is one substance fully dissolv…

, Chapter: 3 -Problem: 33 >> An object has a rest energy of 1 J when its mass is a. 1.1 × 10-17 kg b. 3.3 × 10-9 kg c. 1 kg d. 9 × 1016 kg
Answer Preview: According to Eins…

, Chapter: 18 -Problem: 26 >> Stars at the upper end of the main sequence have a. High temperatures and large masses b. High temperatures and small masses c. Low temperatures and large masses d. Low temperatures and small masses
Answer Preview: a High temperature and large masses Explanation Hydrogen to Helium at a higher rate are fused by H…

, Chapter: 6 -Problem: 27 >> The nature of the force that is responsible for the operation of an electric motor is a. electric b. magnetic c. a combination of electric and magnetic d. either electric or magnetic, depending on the design of the motor
Answer Preview: A certain amount of electric charge is given to a motor w…

, Chapter: 11 -Problem: 13 >> Why do bubbles of gas form in a glass of soda water when it warms up?
Answer Preview: We know that soda water is a solution of ca…

, Chapter: 3 -Problem: 45 >> What happens to the momentum of a car when it comes to a stop?
Answer Preview: According to the principle of conservation of momentum the Momentum …

, Chapter: 18 -Problem: 27 >> Explain how the distance to a star cluster that contains Cepheid variables is determined.
Answer Preview: the intrinsic brightness of those variable stars is strongl…

, Chapter: 6 -Problem: 17 >> (a) A metal sphere with a charge of +1 × 10?5 C is 10 cm from another metal sphere with a charge of ?2 × 10?5 C. Find the magnitude of the attractive force acting on each sphere. (b) The two spheres are brought in contact and again separated by 10 cm. Find the magnitude of the new force acting on each sphere.
Answer Preview: Let distance between two sphere r 10cm r 10 10 2 10 1 m Charge on metal s…

, Chapter: 11 -Problem: 41 >> A concentrated solution of which of the following has the lowest pH? a. hydrochloric acid b. acetic acid c. sodium hydroxide d. ammonia
Answer Preview: Option a is the correct answer pH of 0 1 M …

, Chapter: 3 -Problem: 31 >> A 10,000-kg freight car moving at 2 m/s collides with a stationary 15,000-kg freight car. The two cars couple together and move off at a. 0.8 m/s b. 1 m/s c. 1.3 m/s d. 2 m/s
Answer Preview: m 1 10000 kg m 2 15000 kg …

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, Chapter: 5 -Problem: 38 >> A 2-kg brick has the dimensions 7.5 cm × 15 cm × 30 cm. The pressure the brick exerts on the ground when standing on its smallest face isa. 0.0178 Pa b. 0.0225 Pa c. 178 Pa d. 225 Pa
Answer Preview: Force acting on ground due t…

, Chapter: 12 -Problem: 6 >> An example of an endothermic reaction is a. the dissociation of a salt in water b. the neutralization of an acid by a base c. the freezing of water d. combustion
Answer Preview: Dissociation of many salts is an endothermic process …

, Chapter: 3 -Problem: 11 >> A weightlifter raises a 70-kg barbell from the floor to a height of 2.2 m in 1.2 s. What was his average power output during the lift?
Answer Preview: Mass of the barbell m 70 kg The height up to whic…

, Chapter: 17 -Problem: 48 >> The interior of the moon is probably entirely or almost entirely a. Liquid b. Solid c. Gaseousd. Hollow
Answer Preview: b Solid Explanation Most of the interior of the …

, Chapter: 5 -Problem: 32 >> The Celsius equivalent of a temperature of 120°F is a. 35°C b. 49°F c. 67°C d. 88°C
Answer Preview: Given Temperature in Fahrenheit …

, Chapter: 11 -Problem: 37 >> The formula for iron(III) hydroxide is a. FeOH b. Fe3OH c. Fe(OH)3 d. Fe3(OH)3
Answer Preview: c…

, Chapter: 3 -Problem: 2 >> An object at rest may have a. velocity b. momentum c. kinetic energy d. potential energy
Answer Preview: The object is in rest means it has no velocity …

, Chapter: 18 -Problem: 24 >> The reason stars more than about 100 times as massive as the sun are not found is that a. They would split into double-star systems b. They would be black holes from which no light can escape c. The gravity of such a star would not hold it together against the pressure produced by nuclear reactions in its interior d. The high internal pressures would prevent nuclear reactions from taking place
Answer Preview: Stars die when the atoms in the star make collisions and undergo nuclear fusion whic…

, Chapter: 5 -Problem: 45 >> If a heat engine that exhausts heat to a reservoir at 400 K is to have an efficiency of 33 percent, it must take in heat from a source at a minimum of a. 133 K b. 449 K c. 532 K d. 600 K
Answer Preview: Efficiency of the Heat Engine is given to be 33 Temperature of t…

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, Chapter: 3 -Problem: 17 >> The work done in holding a 50-kg object at a height of 2 m above the floor for 10 s is a. 0 b. 250 J c. 1000 J d. 98,000 J
Answer Preview: The work done in holding a 50 kg object at …

, Chapter: 17 -Problem: 44 >> Most of the craters on the moon are probably the result of a. Volcanic action b. Meteoroid bombardment c. Erosion d. Collisions with asteroids
Answer Preview: Most of the craters on the moon are the result of meteors bombardm…

, Chapter: 5 -Problem: 85 >> Solar energy arrives at a rate of 1.2 kW at a reflecting dish with an area of 1 m2 that focuses the light on a jar that contains 100 g of water initially at 20°C. How long will it take the water to reach 100°C and then boil away if no energy is lost?
Answer Preview: Answer When water is heated to 100C It will evaporate and form water vapour in the atmosphere …

, Chapter: 12 -Problem: 14 >> When the temperature at which a certain reversible reaction occurs is increased, the final amount of the reaction product(s) a. increases b. remains the same c. decreases d. does any of the above, depending on the reaction
Answer Preview: The reaction rates of both forward and backward reactions inc…

, Chapter: 2 -Problem: 55 >> An 80-kg man slides down a rope at constant speed. (a) What is the minimum breaking strength the rope must have? (b) If the rope has precisely this strength, will it support the man if he tries to climb back up?
Answer Preview: In the first case when the man slides down the rope the tensi…

, Chapter: 18 -Problem: 13 >> Why is the sun’s corona ordinarily not visible? How do we know it exists?
Answer Preview: The Sun s corona refers to the outermost part of the Sun s atmosphere The outermost part of the …

, Chapter: 5 -Problem: 51 >> A raft 3 m long, 2 m wide, and 30 cm thick, made from solid balsa wood, is floating in a freshwater lake. How many 65-kg people can it support?
Answer Preview: Answer The Volume V of the raft is the product of its length l width b and hei…

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, Chapter: 2 -Problem: 79 >> A track team on the moon could set new records for the high jump or pole vault (if they did not need space suits, of course) because of the smaller gravitational force. Could sprinters also improve their times for the 100-m dash?
Answer Preview: Sprinters can not improve their timings because their mass remains the same …

, Chapter: 18 -Problem: 8 >> Auroras occur mainly in the polar regions because of the effect of a. the moon b. low temperatures there c. the geomagnetic field d. the earth’s equatorial bulge
Answer Preview: Aurora is a natural phenomenon in which display of a natural colo…

, Chapter: 6 -Problem: 13 >> A charge of +3 × 10?9 C is 50 cm from a charge of ?5 × 10?9 C. Find the magnitude and direction of the force on each charge.
Answer Preview: Given that q 1 3 10 9 c q 2 5 10 9 c Distance between them r 50c…

, Chapter: 11 -Problem: 38 >> A strong acid or base in solution is completely a. dissociated b. neutralized c. hydrolyzed d. precipitated
Answer Preview: The acids are differentiated on the basis of the dissociation int…

, Chapter: 3 -Problem: 71 >> One kilogram of water at 0°C contains 335 kJ of energy more than 1 kg of ice at 0°C. What is the mass equivalent of this amount of energy?
Answer Preview: Given 1 kg water at 0 0 C has 335kJ energy more than …

, Chapter: 17 -Problem: 53 >> Approximately how much time elapses between new moon and full moon?
Answer Preview: Approximately it takes around 29 5 days from new moon to …

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, Chapter: 11 -Problem: 33 >> Do pure acids in the liquid state contain H+ ions? If not, what do such acids consist of?
Answer Preview: Pure acids are covalent rather than ionic substances …

, Chapter: 3 -Problem: 65 >> The length of a rod is measured by several observers, one of whom is stationary with respect to the rod. What must be true of the value obtained by the stationary observer?
Answer Preview: We know that the difference between the original length and the a…

, Chapter: 18 -Problem: 5 >> Why do you think it is useful to put an astronomical telescope in a satellite?
Answer Preview: The reason behind putting astronomical telescope in satell…

, Chapter: 15 -Problem: 26 >> Name the following rocks: (a) A rock consisting of intergrown crystals of quartz; (b) The rock resulting from the metamorphism of limestone; (c) An intrusive igneous rock with the same composition as andesite.
Answer Preview: a Quar…

, Chapter: 5 -Problem: 97 >> Surface water in a tropical ocean is typically at 27°C whereas at a depth of a kilometer or more it is at only about 5°C. It has been proposed to operate heat engines using surface water as the hot reservoir and deep water (pumped to the surface) as the cold reservoir. What would the maximum efficiency of such an engine be? Why might such an engine eventually be a practical proposition even with s
Answer Preview: The maximum efficiency of such an engine would be approximately 47 …

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, Chapter: 3 -Problem: 10 >> A spinning skater whose arms are at her sides then stretches out her arms horizontally. a. She continues to spin at the same rate b. She spins more rapidly c. She spins more slowly d. Any of the choices could be correct, depending on how heavy her arms are
Answer Preview: The angular momentum of a rotating body is defined as the product of its angular speed and its momen…

, Chapter: 18 -Problem: 11 >> How can the composition of the sun be determined?
Answer Preview: The Sun is primarily composed of 74 hydrogen and 25 helium In th…

, Chapter: 6 -Problem: 30 >> A transformer can change a. the voltage of an alternating current b. the power of an alternating current c. alternating current to direct current d. direct current to alternating current
Answer Preview: The working principle of a transformer is that an alternating current in one loop induces an alt…

, Chapter: 10 -Problem: 47 >> Name these compounds: BaH2, Li3PO4, PbO, CuBr2, KOH.
Answer Preview: Chemical Formula Chemical Nam…

, Chapter: 3 -Problem: 1 >> A person holds a 10-kg package 1.2 m above the floor for 1 min. How much work is done?
Answer Preview: Work done will be zero Because work is …

, Chapter: 18 -Problem: 29 >> White dwarfs are stars that are a. At the beginning of their life cycles b. In the middle of their life cycles c. At the end of their life cycles d. Any of these choices is correct.
Answer Preview: option B is the correct answer Reason These are small very hot and dense s…

, Chapter: 6 -Problem: 1 >> The charge on an electron a. is 1 C b. depends on the electron’s mass c. depends on the electron’s size d. is always the same
Answer Preview: Charge of an electron is always …

, Chapter: 11 -Problem: 40 >> A pH of 7 signifies a (an) a. acid solution b. basic solution c. neutral solution d. solution of polar molecules
Answer Preview: On pH scale there are numbers from 0 to 1…

, Chapter: 3 -Problem: 6 >> When the speed of a moving object is halved, a. its KE is halved b. its PE is halved c. its rest energy is halved d. its momentum is halved
Answer Preview: A speed of moving object is halved a K E mv 2 2 K E …

, Chapter: 18 -Problem: 10 >> Sunspots are a. Dark clouds in the sun’s atmosphere b. Regions somewhat cooler than the rest of the sun’s surface c. Regions somewhat hotter than the rest of the sun’s surface d. Of unknown nature
Answer Preview: Sunpots are the darker areas in the sun s surfa…

, Chapter: 6 -Problem: 22 >> The magnetic field shown in Fig. 6-50 is produced bya. two north polesb. two south polesc. a north pole and a south poled. a south pole and an unmagnetized iron bar
Answer Preview: The lines in the diagram are coming inside from somewhere and …

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, Chapter: 2 -Problem: 65 >> An engineer designs a propeller-driven spacecraft. Because there is no air in space, the engineer includes a supply of oxygen as well as a supply of fuel for the motor. What do you think of the idea?
Answer Preview: The propeller rotates using the fuel provided by an internal combustion engine It the…

, Chapter: 17 -Problem: 49 >> How does Pluto compare in size with the moon? With the satellites of the other planets?
Answer Preview: In 18th february 1930 Clyde Tombaugh discovered Pluto and de…

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, Chapter: 11 -Problem: 49 >> The fertilizer ammonium sulfate can be made by using sulfuric acid to neutralize a solution of ammonia in water. Give the overall equation of the process.
Answer Preview: We know that sulfuric acid H 2 SO 4 dissociates into 2H and SO 4 2 ions and ammoni…

, Chapter: 3 -Problem: 11 >> According to the principle of relativity, the laws of physics are the same in all frames of reference a. at rest with respect to one another b. moving toward or away from one another at constant velocity c. moving parallel to one another at constant velocity d. all of these
Answer Preview: According to the principle of relativity Laws of nature are same in all inertial fr…

, Chapter: 18 -Problem: 28 >> The main sequence on the H-R diagram includes a. The sun b. White dwarfs c. Giantsd. Pulsars
Answer Preview: Main sequence on H R diagram includes white dwa…

, Chapter: 18 -Problem: 47 >> Why are there relatively few giant stars in the main sequence?
Answer Preview: A star becomes a giant after all the hydrogen avail…

, Chapter: 5 -Problem: 81 >> Give as many methods as you can think of that will increase the rate of evaporation of a liquid sample. Explain why each method will have this effect.
Answer Preview: The rate of evaporation can be increased by various methods They are …

, Chapter: 11 -Problem: 27 >> How does the reactivity of the chloride ion Cl- compare with the reactivity of the chlorine molecule Cl2? Does the answer depend on temperature?
Answer Preview: The reactivity of Cl 2 gas and Cl ion differ very much Cl 2 is a gas at r…

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, Chapter: 18 -Problem: 25 >> According to the text, the sun’s mass is about 2 × 1030 kg and it loses about 4 × 109 kg per second as its hydrogen is converted into helium. Assuming that the sun has been radiating energy at the same rate as today during the 4.5-billion-year existence of the earth, what percentage of its mass has been lost in this period? What does this imply about the possibility that the intensity of solar rad
Answer Preview: percentage of loss mass lost original mass x 100 It is given that the sun lose…

, Chapter: 18 -Problem: 57 >> What prevents light from escaping from a black hole?
Answer Preview: A black hole is a region of spacetime where gravity is so str…

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, Chapter: 11 -Problem: 47 >> What salt is formed when a solution of potassium hydroxide is neutralized by acetic acid, HC2H3O2? Give the equation of the process.
Answer Preview: Reaction is given as CH3COOH KOH …

, Chapter: 2 -Problem: 87 >> A dishonest grocer installs a 100-kg lead block under the pan of his scale. How much gravitational force does the lead exert on 2 kg of cheese placed on the pan if the centers of mass of the lead and cheese are 0.3 m apart? Compare this force with the weight of 1 g of cheese to see if putting the lead under the scale was worth doing.
Answer Preview: In the figure below the two masses in question are drawn Using Newton s Law of Gra…

, Chapter: 18 -Problem: 16 >> Proxima Centauri, the closest star to the sun, is at a distance of about a. 4 light-years b. 400 light-years c. 4 million light-years d. 4 billion light-years
Answer Preview: Proxima centauri the closest star to th…