Giancoli 7e test bank

Test Bank Physics Principles with Applications -7th Edition-Giancoli

Chapter 6 Sample

Exam

Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1)Substance A has a density of 3 g/cm3 and substance B has a density of 4 g/cm3. In order to obtain1) equal masses of these two substances, what must be the ratio of the volume of A to the volume of B? A)VA3B)VA 3C)VA 1D)VA 4E)VA 3 = = = = = VBVB VB VB VB 4 1 3 3 4 2)A hollow sphere of negligible mass and radius R is completely filled with a liquid so that its 2) density is ρ. You now enlarge the sphere so its radius is 2R and completely fill it with the same liquid. What is the density of the enlarged sphere? A) 8 ρ B) ρ C) ρ/2 D) ρ/8 E) 4 ρ 3)A styrofoam sphere of radius R has a density ρ. You now carefully compress the sphere so its3) radius is R/2. What is the density of the compressed sphere? A) 4 ρ B) ρ 8 C) 8 ρ D) ρ 2E) 2 ρ 4)When a box rests on a round sheet of wood on the ground, it exerts an average pressure p on the4) wood. If the wood is replaced by a sheet that has half the diameter of the original piece, what is the new average pressure? A) p 2 B) p/2 C) 2p D) 4p E) p/4 5)When a heavy metal block is supported by a cylindrical vertical post of radius R, it exerts a force F5) on the post. If the diameter of the post is increased to 2R, what force does the block now exert on the post? A) F/2 B) 2F C) F/4 D) F/2 E) F 6)As shown in the figure, fluid fills a container having several sections. At which of the indicated6) points is the pressure greatest?

AC

B

D

The pressure is the same at each of the labeled points.

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7)Consider a brick that is totally immersed in water, with the long edge of the brick vertical. The7) pressure on the brick is A) greatest on the face with largest area. B) greatest on the top of the brick. C) greatest on the bottom of the brick. D) greatest on the sides of the brick. E) the same on all surfaces of the brick. 8)An air bubble underwater has the same pressure as that of the surrounding water. As the air8) bubble rises toward the surface (and its temperature remains constant), the volume of the air

bubble

A) increases.

B) remains constant.

C) decreases.

D) increases or decreases, depending on the rate it rises.

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

9) A cubical block of stone is lowered at a steady rate into the ocean by a crane, always9)

keeping the top and bottom faces horizontal. Which one of the following graphs best describes the gauge pressure p on the bottom of this block as a function of time t if the block just enters the water at time t = 0 s?

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10) A cubical block of stone is lowered at a steady rate into the ocean by a crane, always10)

keeping the top and bottom faces horizontal. Which one of the following graphs best describes the absolute (total) pressure p on the bottom of this block as a function of time t if the block just enters the water at time t = 0 s?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

11) If atmospheric pressure increases by an amountp, which of the following statements about the11)pressure in a lake is true? (There could be more than one correct choice.) A) The absolute (total) pressure increases, but by an amount less than p. B) The gauge pressure does not change. C) The gauge pressure increases by p. D) The absolute (total) pressure increases byp. E) The absolute (total) pressure does not change. 12) A closed cubical chamber resting on the floor contains oil and a piston. If you push down on the12)piston hard enough to increase the pressure just below the piston by an amount p, which of the following statements is correct? (There could be more than one correct choice.)

A) The pressure everywhere in the oil will increase by p.

B) The pressure at the top of the oil will increase by less than p.

C) The increase in the force on the top of the chamber will be the same as the increase in the force on the bottom of the chamber.

D) The pressure at the bottom of the oil will increase by more than p.

E) The pressure on the sides of the chamber will not increase.

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13)The water pressure to an apartment is increased by the water company. The water enters the13) apartment through an entrance valve at the front of the apartment. Where will the increase in the static water pressure be greatest when no water is flowing in the system? A) at a faucet close to the entrance valve B) at a faucet far from the entrance valve C) There will be no increase in the pressure at the faucets. D) It will be the same at all faucets. 14)A waiter fills your water glass with ice water (containing many ice cubes) such that the liquid14) water is perfectly level with the rim of the glass. As the ice melts, A) the liquid-water level remains flush with the rim of the glass. B) the liquid-water level decreases. C) the liquid water level rises, causing water to run down the outside of the glass. 15)A spherical ball of lead (density 11.3 g/cm3) is placed in a tub of mercury (density 13.6 g/cm3).15) Which answer best describes the result?

The lead will sink to the bottom of the mercury.

The lead ball will float with its top exactly even with the surface of the mercury.

The lead ball will float with about 83% of its volume above the surface of the mercury.

The lead ball will float with about 17% of its volume above the surface of the mercury.

16)A wooden block contains some nails so that its density is exactly equal to that of water. If it is16) placed in a tank of water and released from rest when it is completely submerged, it will A) rise to the surface. B) remain where it is released. C) sink to the bottom. 17)A boat loaded with rocks is floating in a swimming pool. If the rocks are thrown into the pool, the17) water level in the pool, after the rocks have settled to the bottom, A) stays the same.B) rises.C) falls. 18)Salt water has greater density than fresh water. A boat floats in both fresh water and in salt water.18) Where is the buoyant force greater on the boat?

in salt water

in fresh water

The buoyant force is the same in both cases.

19)Salt water is denser than fresh water. A ship floats in both fresh water and salt water. Compared19) to the fresh water, the volume of water displaced in the salt water is A) less. B) the same. C) more. D) Cannot be determined because we do not know the volume of the ship. 20)A steel ball sinks in water but floats in a pool of mercury, which is much denser than water.20) Where is the buoyant force on the ball greater? A) It is the same in both cases.

B) floating on the mercury

C) submerged in the water

D) It cannot be determined from the information given.

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21) A 10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is21)much denser than aluminum. Which one has the greater buoyant force on it? A) the lead B) Both have the same buoyant force. C) the aluminum D) It cannot be determined without knowing their volumes. 22) A piece of iron rests on top of a piece of wood floating in a bathtub. If the iron is removed from the22)wood, and kept out of the water, what happens to the water level in the tub? A) It goes up. B) It does not change. C) It goes down. D) It is impossible to determine from the information given. 23) A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and23)does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?

It does not change.

It goes up.

It goes down.

It cannot be determined without knowing the volumes of the two pieces of wood.

24) As a rock sinks deeper and deeper into water of constant density, what happens to the buoyant24)

force on it if it started above the surface of the water?

A) The buoyant force remains constant.

B) The buoyant force first increases and then remains constant.

C) The buoyant force keeps increasing steadily.

D) The buoyant force steadily decreases.

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SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

25) A cubical block of stone is lowered at a steady rate into the ocean by a crane, always25)

keeping the top and bottom faces horizontal. Which one of the following graphs best describes the buoyant force B on this block as a function of time t if the block just enters the water at time t = 0 s?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

26) A 50-cm3 block of wood is floating on water, and a 50-cm3 chunk of iron is totally submerged in26)the water. Which one has the greater buoyant force on it? A) Both have the same buoyant force. B) the wood C) the iron D) It cannot be determined without knowing their densities. 27) When you blow some air above a paper strip, the paper rises. This happens because27)A) the air above the paper moves faster and the pressure is lower. B) the air above the paper moves slower and the pressure is higher. C) the air above the paper moves slower and the pressure is lower.

D) the air above the paper moves faster and the pressure remains constant.

E) the air above the paper moves faster and the pressure is higher.

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28)Water flows through a pipe. The diameter of the pipe at point B is larger than at point A. Where is28) the water pressure greatest? A) at point A B) at point B C) It is the same at both A and B. 29)Two horizontal pipes are the same length, but pipe B has twice the diameter of pipe A. Water29) undergoes viscous flow in both pipes, subject to the same pressure difference across the lengths of the pipes. If the flow rate in pipe A is Q =V, what is the flow rate in pipe B? t A) 4QB) 2QC) 8QD) Q 2E) 16Q 30)Two horizontal pipes have the same diameter, but pipe B is twice as long as pipe A. Water30) undergoes viscous flow in both pipes, subject to the same pressure difference across the lengths of the pipes. If the flow rate in pipe B is Q = Vwhat is the flow rate in pipe A? t A) 8QB) Q 2C) 4QD) 2QE) 16Q 31)A plastic block of dimensions 2.00 cm × 3.00 cm × 4.00 cm has a mass of 30.0 g. What is its density?31) A) 1.60 g/cm3B) 0.80 g/cm3 C) 1.20 g/cm3D) 1.25 g/cm3 32)A compressed gas with a total mass of 107 kg is stored in a spherical container having a radius of32) 0.521 m. What is the density of the compressed gas? A) 161 kg/m3B) 134 kg/m3 C) 110 kg/m3D) 181 kg/m3 33)The density of material at the center of a neutron star is approximately 1.00 × 1018 kg/m3. What is33) the mass of a cube of this material that is 1.76 microns on each side. (One micron is equal to 1.00 × 10–6 m.) A) 5.45 kgB) 6.70 kg C) 6.16 kg D) 4.74 kg 34)Under standard conditions, the density of air is 1.29 kg/m3. What is the mass of the air inside a34) room measuring 4.0 m × 3.0 m × 2.0 m? A) 3.1 kgB) 1.9 kgC) 0.32 kgD) 19 kgE) 31 kg 35)A round coin has a diameter of 19.55 mm, a thickness of 1.55 mm, and a mass of 2.50 g. What is its35) density?

5 × 103 kg/m3

34 × 103 kg/m3

68 × 103 kg/m3

86 × 10–4 kg/m3

37 × 103 kg/m3

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36)A 1938 nickel has a diameter of 21.21 mm, a thickness of 1.95 mm, and weighs 0.04905 N. What is36) its density? A) 1.37 × 10–4 kg/m3 B) 7.26 × 103 kg/m3 C) 3.63 × 103 kg/m3 D) 1.82 × 103 kg/m3 E) 19.3 × 103 kg/m3 37)How many grams of ethanol (density 0.80 g/cm3) should be added to 5.0 g of chloroform (density37) 1.5 g/cm3) if the resulting mixture is to have a density of 1.2 g/cm3? Assume that the fluids do not change their volumes when they are mixed. A) 1.6 gB) 2.4 gC) 4.4 gD) 2.0 gE) 1.8 g 38)A 100-kg person sits on a 5-kg bicycle. The total weight is borne equally by the two wheels of the38) bicycle. The tires are 2.0 cm wide and are inflated to a gauge pressure of 8.0 × 105 Pa. What length of each tire is in contact with the ground? A) 2.4 cmB) 1.6 cmC) 6.4 cmD) 1.8 cmE) 3.2 cm 39)The weight of a 1200-kg car is supported equally by the four tires, which are inflated to the same39) gauge pressure. What gauge pressure is required so the area of contact of each tire with the road is 100 cm2? A) 2.9 × 105 PaB) 12 × 105 Pa C) 2.9 × 104 PaD) 12 × 104 Pa 40)One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated40) with such storms. Assume that the air pressure inside of a sealed house is 1.02 atm when a hurricane hits. The hurricane rapidly decreases the external air pressure to 0.910 atm. What net outward force is exerted on a square window of the house that is 2.03 m on each side? (1.00 atm = 1.01 × 105 Pa) A) 4.59 × 104 NB) 5.42 × 105 N C) 4.82 × 105 ND) 5.19 × 104 N 41)Calculate the pressure exerted on the ground due to the weight of a 79-kg person standing on one41) foot. if the bottom of the person’s foot is 13 cm wide and 28 cm long. A) 2.2 × 103 PaB) 5.3 × 104 Pa C) 2.1 × 104 PaD) 4.8 × 104 Pa 42)A brick weighs 50.0 N, and measures 30.0 cm × 10.0 cm × 4.00 cm. What is the maximumpressure42) it can exert on a horizontal surface due to its weight? A) 1.25 kPaB) 12.5 Pa C) 12.5 kPaD) 1.25 Pa 43)A person weighing 900 N is standing on snowshoes. Each snowshoe has area 2500 cm 2 and has43) negligible weight. What pressure does this person’s weight exert on the snow? A) 1800 N/m2B) 0.36 N/m2 C) 0.18 N/m2D) 3600 N/m2

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44) A water tank is filled to a depth of 10 m, and the bottom of the tank is 20 m above ground. A44)

water-filled hose that is 2.0 cm in diameter extends from the bottom of the tank to the ground, but no water is flowing in this hose. The water pressure at ground level in the hose is closest to which of the following values? The density of water is 1000 kg/m3.

9 × 105 N/m2

2 N/m2

0 × 104 N/m2

The question cannot be answered because the cross sectional area of the tank is needed.

45) The Aswan High Dam on the Nile River in Egypt is 111 m high. What is the gauge pressure in the45)water at the foot of the dam? The density of water is 1000 kg/m3. A) 1.09× 106 Pa B) 1.16× 106 Pa C) 1.11× 105 Pa D) 1.11× 102 Pa E) 1.09× 103 Pa 46) The deepest point of the Pacific Ocean is 11,033 m, in the Mariana Trench. What is the gauge46)pressure in the water at that point? The density of seawater is 1025 kg/m3. A) 1.11× 108 Pa B) 3.33× 108 Pa C) 8.88× 107 Pa D) 2.22× 108 Pa E) 5.55× 107 Pa 47) The Tonga Trench in the Pacific Ocean is 36,000 feet deep. Assuming that sea water has an47)average density of 1.04 g/cm3, calculate the absolute (total) pressure at the bottom of the trench in atmospheres. (1.00 in = 2.54 cm, 1.00 atm = 1.01 × 105 Pa) A) 1.1 × 108 atm B) 1.1 × 103 atm C) 1.1 × 105 atm D) 1.1 × 106 atm E) 2.1 atm 48) What force does the water exert (in addition to that due to atmospheric pressure) on a submarine48)window of radius 44.0 cm at a depth of 9400 m in sea water? The density of sea water is 1025 kg/m3. A) 5.74× 1011 N B) 5.74× 107 N C) 2.87× 107 N D) 1.83× 107 N E) 2.87× 1011 N

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49)A cubical box 25.0 cm on each side is immersed in a fluid. The pressure at the top surface of the49) box is 109.40 kPa and the pressure on the bottom surface is 112.00 kPa. What is the density of the fluid?1000 kg/m3 A) B) 1060 kg/m3 C)1030 kg/m3 D)1120 kg/m3 E) 1090 kg/m3 50)A circular window 30 cm in diameter in a submarine can withstand a net maximum force of 5.20 ×50) 105 N without damage. What is the maximum depth in a fresh-water lake to which the submarine can go without damaging the window? The density of fresh water is 1000 kg/m 3. A)680 mB) 1200 mC) 740 mD) 750 m 51)A container has a vertical tube, whose inner radius is 24.00 mm, connected to it at its side, as51) shown in the figure. An unknown liquid reaches level A in the container and level B in the tube

–level A being 5.0 cm higher than level B. The liquid supports a 20-cm high column of oil, between levels B and C, whose density is 570 kg/m3. The mass of the oil is closest to

A) 1000B) 410C) 210D) 620E) 820 52) A container has a vertical tube, whose inner radius is 12.00 mm, connected to it at its side, as52)

shown in the figure. An unknown liquid reaches level A in the container and level B in the tube –level A being 5.0 cm higher than level B. The liquid supports a 20-cm high column of oil, between levels B and C, whose density is 320 kg/m3. The gauge pressure at level B is closest to

A) 790 Pa B) 940 Pa C) 630 Pa D) 310 Pa E) 470 Pa

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53) A container has a vertical tube, whose inner radius is 20.00 mm, connected to it at its side, as53)

shown in the figure. An unknown liquid reaches level A in the container and level B in the tube –level A being 5.0 cm higher than level B. The liquid supports a 20-cm high column of oil, between levels B and C, whose density is 900 kg/m3. The density of the unknown liquid is closest to

3300 kg/m3

3100 kg/m3

2800 kg/m3

3900 kg/m3

3600 kg/m3

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

54) As shown in the figure, a large open tank contains a layer of oil ( density 450 kg/m 3)54)

floating on top of a layer of water (density 1000 kg/m3) that is 3.0 m thick, as shown in the sketch. What must be the thickness of the oil layer if the gauge pressure at the bottom of the tank is to be 8.5 x 104 Pa?

55) A container consists of two vertical cylindrical columns of different diameter connected by 55) a narrow horizontal section, as shown in the figure. The open faces of the two columns are closed by very light plates that can move up and down without friction. The tube diameter

at A is 35.0 cm and at B it is 10.2 cm. This container is filled with oil of density 0.820 g/cm3. If a 125-kg object is placed on the larger plate at A, how much mass should be placed on the smaller plate at B to balance it?

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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

56) A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal56)areas, filled with oil and capped at both ends with tight-fitting pistons. The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm. The car rests on the piston on the wider arm of the U-tube. The pistons are initially at the same level. What is the initial force that must be applied to the smaller piston in order to start lifting the car? For purposes of this problem, neglect the weight of the pistons. A) 2.90 kNB) 727 NC) 926 ND) 3.33 kNE) 1.20 kN 57) A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal57)areas, filled with oil with a density of 800 kg/m3 and capped at both ends with tight-fitting pistons. The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm. The car rests on the piston on the wider arm of the U-tube. The pistons are initially at the same level. What is the force that must be applied to the smaller piston in order to lift the car after it has been raised 1.20 m? For purposes of this problem, neglect the weight of the pistons. A) 1.20 kNB) 1.88 kNC) 1.96 kND) 3.67 kNE) 0.954 kN 58) A 500-N weight sits on the small piston of a hydraulic machine. The small piston has an area of58)2.0 cm2. If the large piston has an area of 40 cm2, how much weight can the large piston support? Assume the pistons each have negligible weight. A) 40000 NB) 25 NC) 10000 ND) 500 N 59) In a hydraulic garage lift, the small piston has a radius of 5.0 cm and the large piston has a radius59)of 15 cm. What force must be applied on the small piston in order to lift a car weighing 20,000 N on the large piston? Assume the pistons each have negligible weight. A) 6.7 × 103 NB) 2.9 × 103 NC) 5.0 × 103 ND) 2.2 × 103 N 60) A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston. What force needs to be60)applied to a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible weight. A) 520 NB) 5200 NC) 2600 N D) 260 N

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

61) The small piston of a hydraulic lift has a diameter of 8.0 cm, and its large piston has a61)

diameter of 40 cm. The lift raises a load of 15,000 N. Assume the pistons each have negligible weight.

(a) Determine the force that must be applied to the small piston.

(b) Determine the pressure applied to the fluid in the lift.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

62)A block of metal weighs 40 N in air and 30 N in water. What is the buoyant force on the block due62) to the water? The density of water is 1000 kg/m 3. A) 40 NB) 70 NC) 10 N D) 30 N 63)If a ship has a mass of 10 million kilograms, what volume of fresh water must it displace in order63) to float? The density of water is 1000 kg/m3. A) 1012 m3B) 1010 m3C) 107 m3D) 104 m3E) 108 m3

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