# Quiz 13: Fluids

Physics & Astronomy

Q 1Q 1

Substance A has a density of 3 g/cm

^{3}and substance B has a density of 4 g/cm^{3}. In order to obtain equal masses of these two substances, what must be the ratio of the volume of A to the volume of B? A) = B) = C) = D) = E) =Free

Multiple Choice

B

Q 2Q 2

A hollow sphere of negligible mass and radius R is completely filled with a liquid so that its 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)4 ρ
C)ρ/2
D)ρ
E)ρ/8

Free

Multiple Choice

D

Q 3Q 3

A styrofoam sphere of radius R has a density ρ. You now carefully compress the sphere so its radius is R/2. What is the density of the compressed sphere?
A)2 ρ
B)4 ρ
C)ρ
D)ρ
E)8 ρ

Free

Multiple Choice

E

Q 4Q 4

When a box rests on a round sheet of wood on the ground, it exerts an average pressure p on the 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)4p
B)2p
C)p
D)p/2
E)p/4

Free

Multiple Choice

Q 5Q 5

When a heavy metal block is supported by a cylindrical vertical post of radius R, it exerts a force F 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/4
B)F/2
C)F/
D)F
E)2F

Free

Multiple Choice

Q 6Q 6

As shown in the figure, fluid fills a container having several sections. At which of the indicated points is the pressure greatest?
A)A
B)B
C)C
D)D
E)The pressure is the same at each of the labeled points.

Free

Multiple Choice

Q 7Q 7

Consider a brick that is totally immersed in water, with the long edge of the brick vertical. The pressure on the brick is
A)the same on all surfaces of the brick.
B)greatest on the face with largest area.
C)greatest on the top of the brick.
D)greatest on the sides of the brick.
E)greatest on the bottom of the brick.

Free

Multiple Choice

Q 8Q 8

An air bubble underwater has the same pressure as that of the surrounding water. As the air bubble rises toward the surface (and its temperature remains constant), the volume of the air bubble
A)increases.
B)decreases.
C)remains constant.
D)increases or decreases, depending on the rate it rises.

Free

Multiple Choice

Q 9Q 9

If atmospheric pressure increases by an amount Δp, which of the following statements about the pressure in a lake is true? (There could be more than one correct choice.)
A)The absolute (total)pressure does not change.
B)The absolute (total)pressure increases, but by an amount less than Δp.
C)The absolute (total)pressure increases by Δp.
D)The gauge pressure increases by Δp.
E)The gauge pressure does not change.

Free

Multiple Choice

Q 10Q 10

A closed cubical chamber resting on the floor contains oil and a piston. If you push down on the piston hard enough to increase the pressure just below the piston by an amount Δp, 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 Δp.
B)The pressure at the bottom of the oil will increase by more than Δp.
C)The pressure at the top of the oil will increase by less than Δp.
D)The pressure on the sides of the chamber will not increase.
E)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.

Free

Multiple Choice

Q 11Q 11

The water pressure to an apartment is increased by the water company. The water enters the 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)It will be the same at all faucets.
D)There will be no increase in the pressure at the faucets.

Free

Multiple Choice

Q 12Q 12

A waiter fills your water glass with ice water (containing many ice cubes)such that the liquid 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 rises, causing water to run down the outside of the glass.
C)the liquid-water level decreases.

Free

Multiple Choice

Q 13Q 13

A spherical ball of lead (density 11.3 g/cm

^{3})is placed in a tub of mercury (density 13.6 g/cm^{3}). Which answer best describes the result? A)The lead ball will float with about 83% of its volume above the surface of the mercury. B)The lead ball will float with its top exactly even with the surface of the mercury. C)The lead ball will float with about 17% of its volume above the surface of the mercury. D)The lead will sink to the bottom of the mercury.Free

Multiple Choice

Q 14Q 14

A wooden block contains some nails so that its density is exactly equal to that of water. If it is placed in a tank of water and released from rest when it is completely submerged, it will
A)rise to the surface.
B)sink to the bottom.
C)remain where it is released.

Free

Multiple Choice

Q 15Q 15

A boat loaded with rocks is floating in a swimming pool. If the rocks are thrown into the pool, the water level in the pool, after the rocks have settled to the bottom,
A)rises.
B)falls.
C)stays the same.

Free

Multiple Choice

Q 16Q 16

Salt water has greater density than fresh water. A boat floats in both fresh water and in salt water. Where is the buoyant force greater on the boat?
A)in salt water
B)in fresh water
C)The buoyant force is the same in both cases.

Free

Multiple Choice

Q 17Q 17

Salt water is denser than fresh water. A ship floats in both fresh water and salt water. Compared to the fresh water, the volume of water displaced in the salt water is
A)more.
B)less.
C)the same.
D)Cannot be determined because we do not know the volume of the ship.

Free

Multiple Choice

Q 18Q 18

A steel ball sinks in water but floats in a pool of mercury, which is much denser than water. Where is the buoyant force on the ball greater?
A)floating on the mercury
B)submerged in the water
C)It is the same in both cases.
D)It cannot be determined from the information given.

Free

Multiple Choice

Q 19Q 19

A 10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. Which one has the greater buoyant force on it?
A)the aluminum
B)the lead
C)Both have the same buoyant force.
D)It cannot be determined without knowing their volumes.

Free

Multiple Choice

Q 20Q 20

A piece of iron rests on top of a piece of wood floating in a bathtub. If the iron is removed from the wood, and kept out of the water, what happens to the water level in the tub?
A)It goes up.
B)It goes down.
C)It does not change.
D)It is impossible to determine from the information given.

Free

Multiple Choice

Q 21Q 21

A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and 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?
A)It goes up.
B)It goes down.
C)It does not change.
D)It cannot be determined without knowing the volumes of the two pieces of wood.

Free

Multiple Choice

Q 22Q 22

As a rock sinks deeper and deeper into water of constant density, what happens to the buoyant force on it if it started above the surface of the water?
A)The buoyant force keeps increasing steadily.
B)The buoyant force remains constant.
C)The buoyant force first increases and then remains constant.
D)The buoyant force steadily decreases.

Free

Multiple Choice

Q 23Q 23

A 50-cm

^{3}block of wood is floating on water, and a 50-cm^{3}chunk of iron is totally submerged in the water. Which one has the greater buoyant force on it? A)the wood B)the iron C)Both have the same buoyant force. D)It cannot be determined without knowing their densities.Free

Multiple Choice

Q 24Q 24

When you blow some air above a paper strip, the paper rises. This happens because
A)the air above the paper moves faster and the pressure is higher.
B)the air above the paper moves faster and the pressure is lower.
C)the air above the paper moves faster and the pressure remains constant.
D)the air above the paper moves slower and the pressure is higher.
E)the air above the paper moves slower and the pressure is lower.

Free

Multiple Choice

Q 25Q 25

Water flows through a pipe. The diameter of the pipe at point B is larger than at point A. Where is the water pressure greatest?
A)at point A
B)at point B
C)It is the same at both A and B.

Free

Multiple Choice

Q 26Q 26

Two horizontal pipes are the same length, but pipe B has twice the diameter of pipe A. Water 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 = , what is the flow rate in pipe B?
A)2Q
B)4Q
C)8Q
D)16Q
E)Q

Free

Multiple Choice

Q 27Q 27

Two horizontal pipes have the same diameter, but pipe B is twice as long as pipe A. Water 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 = what is the flow rate in pipe A?
A)2Q
B)4Q
C)8Q
D)16Q
E)Q

Free

Multiple Choice

Q 28Q 28

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?
A)0.80 g/cm

^{3}B)1.20 g/cm^{3}C)1.25 g/cm^{3}D)1.60 g/cm^{3}Free

Multiple Choice

Q 29Q 29

A compressed gas with a total mass of is stored in a spherical container having a radius of 0.521 m. What is the density of the compressed gas?
A)181 kg/m

^{3}B)110 kg/m^{3}C)134 kg/m^{3}D)161 kg/m^{3}Free

Multiple Choice

Q 30Q 30

The density of material at the center of a neutron star is approximately 1.00 × 10

^{18}kg/m^{3}. What is the mass of a cube of this material that is on each side. (One micron is equal to 1.00 × 10^{-6}m.) A)5.45 kg B)4.74 kg C)6.16 kg D)6.70 kgFree

Multiple Choice

Q 31Q 31

Under standard conditions, the density of air is 1.29 kg/m

^{3}. What is the mass of the air inside a room measuring 4.0 m × 3.0 m × 2.0 m? A)0.32 kg B)3.1 kg C)31 kg D)1.9 kg E)19 kgFree

Multiple Choice

Q 32Q 32

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 its density?
A)5.37 × 10

^{3}kg/m^{3}B)21.5 × 10^{3}kg/m^{3}C)1.34 × 10^{3}kg/m^{3}D)2.68 × 10^{3}kg/m^{3}E)1.86 × 10^{-4}kg/m^{3}Free

Multiple Choice

Q 33Q 33

A 1938 nickel has a diameter of 21.21 mm, a thickness of 1.95 mm, and weighs 0.04905 N. What is its density?
A)1.37 × 10

^{-4}kg/m^{3}B)1.82 × 10^{3}kg/m^{3}C)19.3 × 10^{3}kg/m^{3}D)3.63 × 10^{3}kg/m^{3}E)7.26 × 10^{3}kg/m^{3}Free

Multiple Choice

Q 34Q 34

How many grams of ethanol (density 0.80 g/cm

^{3})should be added to 5.0 g of chloroform (density 1.5 g/cm^{3})if the resulting mixture is to have a density of 1.2 g/cm^{3}? Assume that the fluids do not change their volumes when they are mixed. A)2.0 g B)2.4 g C)1.8 g D)4.4 g E)1.6 gFree

Multiple Choice

Q 35Q 35

A 100-kg person sits on a 5-kg bicycle. The total weight is borne equally by the two wheels of the bicycle. The tires are 2.0 cm wide and are inflated to a gauge pressure of 8.0 × 10

^{5}Pa. What length of each tire is in contact with the ground? A)1.6 cm B)1.8 cm C)3.2 cm D)2.4 cm E)6.4 cmFree

Multiple Choice

Q 36Q 36

The weight of a 1200-kg car is supported equally by the four tires, which are inflated to the same gauge pressure. What gauge pressure is required so the area of contact of each tire with the road is 100 cm

^{2}? A)12 × 10^{5}Pa B)12 × 10^{4}Pa C)2.9 × 10^{5}Pa D)2.9 × 10^{4}PaFree

Multiple Choice

Q 37Q 37

One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated 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 on each side? (1.00 atm = 1.01 × 10

^{5}Pa) A)4.59 × 10^{4}N B)5.19 × 10^{4}N C)4.82 × 10^{5}N D)5.42 × 10^{5}NFree

Multiple Choice

Q 38Q 38

Calculate the pressure exerted on the ground due to the weight of person standing on one foot. if the bottom of the person's foot is wide and long.
A)2.1 × 10

^{4}Pa B)2.2 × 10^{3}Pa C)4.8 × 10^{4}Pa D)5.3 × 10^{4}PaFree

Multiple Choice

Q 39Q 39

A brick weighs 50.0 N, and measures 30.0 cm × 10.0 cm × 4.00 cm. What is the maximum pressure it can exert on a horizontal surface due to its weight?
A)1.25 Pa
B)12.5 Pa
C)1.25 kPa
D)12.5 kPa

Free

Multiple Choice

Q 40Q 40

A person weighing 900 N is standing on snowshoes. Each snowshoe has area 2500 cm

^{2}and has negligible weight. What pressure does this person's weight exert on the snow? A)0.18 N/m^{2}B)0.36 N/m^{2}C)1800 N/m^{2}D)3600 N/m^{2}Free

Multiple Choice

Q 41Q 41

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

^{3}. A)3.9 × 10^{5}N/m^{2}B)2.0 × 10^{4}N/m^{2}C)9.2 N/m^{2}D)The question cannot be answered because the cross sectional area of the tank is needed.Free

Multiple Choice

Q 42Q 42

The Aswan High Dam on the Nile River in Egypt is 111 m high. What is the gauge pressure in the water at the foot of the dam? The density of water is 1000 kg/m

^{3}. A)1.09 × 10^{6}Pa B)1.16 × 10^{6}Pa C)1.09 × 10^{3}Pa D)1.11 × 10^{5}Pa E)1.11 × 10^{2}PaFree

Multiple Choice

Q 43Q 43

The deepest point of the Pacific Ocean is 11,033 m, in the Mariana Trench. What is the gauge pressure in the water at that point? The density of seawater is 1025 kg/m

^{3}. A)5.55 × 10^{7}Pa B)8.88 × 10^{7}Pa C)1.11 × 10^{8}Pa D)2.22 × 10^{8}Pa E)3.33 × 10^{8}PaFree

Multiple Choice

Q 44Q 44

The Tonga Trench in the Pacific Ocean is 36,000 feet deep. Assuming that sea water has an average density of 1.04 g/cm

^{3}, calculate the absolute (total)pressure at the bottom of the trench in atmospheres. (1.00 in = 2.54 cm, 1.00 atm = 1.01 × 10^{5}^{ Pa)}A)1.1 × 10^{3}atm B)1.1 × 10^{8}atm C)1.1 × 10^{5}atm D)1.1 × 10^{6}atm E)2.1 atmFree

Multiple Choice

Q 45Q 45

What force does the water exert (in addition to that due to atmospheric pressure)on a submarine window of radius 44.0 cm at a depth of 9400 m in sea water? The density of sea water is 1025 kg/m

^{3}. A)5.74 × 10^{7}_{ N }B)5.74 × 10^{11}_{ N}C)2.87 × 10^{11}_{ N}D)1.83 × 10^{7}_{ N}E)2.87 × 10^{7}_{ N}Free

Multiple Choice

Q 46Q 46

A cubical box 25.0 cm on each side is immersed in a fluid. The pressure at the top surface of the box is 109.40 kPa and the pressure on the bottom surface is 112.00 kPa. What is the density of the fluid?
A)1000 kg/m

^{3}B)1030 kg/m^{3}C)1060 kg/m^{3}D)1090 kg/m^{3}E)1120 kg/m^{3}Free

Multiple Choice

Q 47Q 47

A circular window 30 cm in diameter in a submarine can withstand a net maximum force of 5.20 × 10

^{5}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 m B)740 m C)1200 m D)750 mFree

Multiple Choice

Q 48Q 48

A container has a vertical tube, whose inner radius is 24.00 mm, connected to it at its side, as 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 The mass of the oil is closest to
A)210
B)410
C)620
D)820
E)1000

Free

Multiple Choice

Q 49Q 49

A container has a vertical tube, whose inner radius is 12.00 mm, connected to it at its side, as 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 The gauge pressure at level B is closest to
A)630 Pa
B)310 Pa
C)470 Pa
D)790 Pa
E)940 Pa

Free

Multiple Choice

Q 50Q 50

A container has a vertical tube, whose inner radius is 20.00 mm, connected to it at its side, as 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 The density of the unknown liquid is closest to
A)3600 kg/
B)3900 kg/
C)2800 kg/
D)3100 kg/
E)3300 kg/

Free

Multiple Choice

Q 51Q 51

As shown in the figure, a large open tank contains a layer of oil ( density 450 kg/ )floating on top of a layer of water (density 1000 kg/m

^{3})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 beFree

Essay

Q 52Q 52

A container consists of two vertical cylindrical columns of different diameter connected by 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/cm

^{3}. 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?Free

Essay

Q 53Q 53

A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal 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)727 N
B)926 N
C)2.90 kN
D)3.33 kN
E)1.20 kN

Free

Multiple Choice

Q 54Q 54

A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal areas, filled with oil with a density of 800 kg/m

^{3}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)0.954 kN B)1.88 kN C)1.96 kN D)3.67 kN E)1.20 kNFree

Multiple Choice

Q 55Q 55

A 500-N weight sits on the small piston of a hydraulic machine. The small piston has an area of 2.0 cm

^{2}. If the large piston has an area of 40 cm^{2}, how much weight can the large piston support? Assume the pistons each have negligible weight. A)25 N B)500 N C)10000 N D)40000 NFree

Multiple Choice

Q 56Q 56

In a hydraulic garage lift, the small piston has a radius of 5.0 cm and the large piston has a radius 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 × 10

^{3}N B)5.0 × 10^{3}N C)2.9 × 10^{3}N D)2.2 × 10^{3}NFree

Multiple Choice

Q 57Q 57

A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston. What force needs to be applied to a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible weight.
A)260 N
B)520 N
C)2600 N
D)5200 N

Free

Multiple Choice

Q 58Q 58

The small piston of a hydraulic lift has a diameter of 8.0 cm, and its large piston has a 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.

Free

Essay

Q 59Q 59

A block of metal weighs 40 N in air and 30 N in water. What is the buoyant force on the block due to the water? The density of water is 1000 kg/m

^{3}. A)10 N B)30 N C)40 N D)70 NFree

Multiple Choice

Q 60Q 60

If a ship has a mass of 10 million kilograms, what volume of fresh water must it displace in order to float? The density of water is 1000 kg/m

^{3}. A)10^{10}m^{3}B)10^{12}m^{3}C)10^{4}m^{3}D)10^{7}m^{3}E)10^{8}m^{3}Free

Multiple Choice

Q 61Q 61

An object has a volume of 4.0 m

^{3}and weighs 40,000 N. What will its apparent weight be in water of density 1000 kg/m^{3}? A)40,000 N B)39,200 N C)9,800 N D)800 NFree

Multiple Choice

Q 62Q 62

A 4.0-kg cylinder of solid iron is supported by a string while submerged in water. What is the tension in the string? The density of iron is 7860 kg/m

^{3}and that of water is 1000 kg/m^{3}. A)2.5 N B)20 N C)24 N D)34 N E)40 NFree

Multiple Choice

Q 63Q 63

What buoyant force does a 0.60-kg solid gold crown experience when it is immersed in water? The density of gold is 19.3 × 10

^{3}kg/m^{3}and that of water is 1000 kg/m^{3}. A)3.0 × 10^{-5}N B)3.0 × 10^{-4}N C)3.0 × 10^{-2}N D)0.30 NFree

Multiple Choice

Q 64Q 64

A crane lifts a steel submarine of density 7800 kg/m

^{3}and mass 20,000 kg. What is the tension in the lifting cable (a)when the submarine is submerged in water of density 1000 kg/m^{3}, and (b)when it is entirely out of the water? A)(a)2.0 × 10^{5}N (b)1.7 × 10^{5}N B)(a)1.7 × 10^{5}N (b)2.0 × 10^{5}N C)(a)2.6 × 10^{3}N (b)2.0 × 10^{5}N D)(a)2.0 × 10^{5}N (b)2.6 × 10^{3}NFree

Multiple Choice

Q 65Q 65

An object weighs 7.84 N when it is in air and 6.86 N when it is immersed in water of density 1000 kg/m

^{3}. What is the density of the object? A)6000 kg/m^{3}B)7000 kg/m^{3}C)8000 kg/m^{3}D)9000 kg/m^{3}Free

Multiple Choice

Q 66Q 66

When a container of water is placed on a laboratory scale, the scale reads 120 g. Now a 20-g piece of copper (of density 8.9 g/cm

^{3})is suspended from a thread and lowered into the water, not touching the bottom of the container. What will the scale now read? The density of water is 1.0 g/cm^{3}. A)120 g B)122 g C)138 g D)140 gFree

Multiple Choice

Q 67Q 67

A piece of aluminum with a mass of 1.0 kg and density of 2700 kg/m

^{3}is suspended from a light cord and then completely immersed in a container of water having density 1000 kg/m^{3}. (a)Determine the volume of the piece of aluminum. (b)Determine the tension in the cord when the aluminum is immersed in the container of water.Free

Essay

Q 68Q 68

A cylindrical rod of length 12 cm and diameter 2.0 cm will just barely float in water of density 1000 kg/m

^{3}. What is its mass? A)38 g B)75 g C)150 g D)300 gFree

Multiple Choice

Q 69Q 69

A rectangular box of negligible mass measures 5.0 m long, 1.0 m wide, and 0.50 m high. How many kilograms of mass can be loaded onto the box before it sinks in a lake having water of density 1000 kg/m

^{3}? A)0.50 × 10^{3}kg B)1.5 × 10^{3}kg C)2.5 × 10^{3}kg D)3.5 × 10^{3}kgFree

Multiple Choice

Q 70Q 70

A 1.00-m

^{3}object floats in water with 20.0% of its volume above the waterline. What does the object weigh out of the water? The density of water is 1000 kg/m^{3}. A)1,960 N B)7,840 N C)9,800 N D)11,800 NFree

Multiple Choice

Q 71Q 71

An object floats with half its volume beneath the surface of the water. The weight of the displaced water is 2000 N. What is the weight of the object? The density of water is 1000 kg/m

^{3}. A)1000 N B)2000 N C)4000 N D)It cannot be determined because we do not know the volume of the object.Free

Multiple Choice

Q 72Q 72

A solid object floats in water with three-fourths of its volume beneath the surface. What is the object's density? The density of water is 1000 kg/m

^{3}. A)1333 kg/m^{3}B)1000 kg/m^{3}C)750 kg/m^{3}D)250 kg/m^{3}Free

Multiple Choice

Q 73Q 73

A 200-N object floats with three-fourths of its volume beneath the surface of the water. What is the buoyant force on the object? The density of water is 1000 kg/m

^{3}. A)50 N B)150 N C)200 N D)267 N E)It cannot be determined because we do not know the volume of the object.Free

Multiple Choice

Q 74Q 74

A polar bear of mass 200 kg stands on an ice floe that is a uniform 1.0 m thick. What is the minimum area of the floe that will just support the bear in saltwater of density 1030 kg/m

^{3}? The density of ice is 980 kg/m^{3}. A)1.0 m^{2}B)2.0 m^{2}C)3.0 m^{2}D)4.0 m^{2}Free

Multiple Choice

Q 75Q 75

A wooden raft has a mass of 55 kg. When empty it floats in water (density with 64% of its volume submerged. What maximum mass of sand can be put on the raft without sinking it?

Free

Essay

Q 76Q 76

A hollow steel ball of diameter 3.0 m just barely floats in water. What is the wall thickness of the ball? (ρ

_{Fe}= 7.87 g/cm^{3}, ρ_{water }= 1.00 g/cm^{3}) A)6.6 cm B)37 cm C)131 cm D)79 cmFree

Multiple Choice

Q 77Q 77

A 200-kg flat-bottomed boat floats in fresh water, which has a density of 1000 kg/m

^{3}. If the base of the boat is 1.42 m wide and 4.53 m long, to what depth is the bottom of the boat submerged when it carries three passengers whose total mass is A)7.10 cm B)7.53 cm C)7.95 cm D)8.52 cmFree

Multiple Choice

Q 78Q 78

A 4.7-kg solid sphere, made of metal whose density is 4000 kg/ , hangs by a light cord. When the sphere is immersed in water, what is the tension in the cord? The density of water is 1000 kg/m

^{3}. A)35 N B)40 N C)46 N D)52 N E)58 NFree

Multiple Choice

Q 79Q 79

A solid sphere of mass 8.6 kg, made of metal whose density is 3400 kg/ , hangs by a cord. When the sphere is immersed in a liquid of unknown density, the tension in the cord is 38 N. The density of the liquid is closest to which one of the following values?
A)1900 kg/
B)1700 kg/
C)1600 kg/
D)1500 kg/
E)1400 kg/

Free

Multiple Choice

Q 80Q 80

A barge is 10 m wide and 60 m long and has vertical sides. The bottom of the boat is 1.2 m below the water surface. What is the weight of the barge and its cargo, if it is floating in fresh water of density 1000 kg/m

^{3}? A)3.5 MN B)6.4 MN C)6.8 MN D)7.1 MN E)9.5 MNFree

Multiple Choice

Q 81Q 81

A barge with vertical sides is 10 m wide and 60 m long and is floating in fresh water of density 1000 kg/m

^{3}. How much deeper into the water does the barge sink when 3.0 x 10^{5}kg of coal are loaded on the barge? A)25 cm B)50 cm C)75 cm D)1.0 m E)1.5 mFree

Multiple Choice

Q 82Q 82

A hot air balloon along with its cargo has a mass of 4.0 x 10

^{5}kg, and it holds 7.0 x 10^{5}m^{3}of hot air. It is floating at a constant height in air with a density of 1.29 kg/m^{3}. What is the density of the hot air in the balloon? A)1.4 kg/m^{3}B)0.72 kg/m^{3}C)0.57 kg/m^{3}D)0.86 kg/m^{3}E)0.43 kg/m^{3}Free

Multiple Choice

Q 83Q 83

A person who weighs 550 N empties her lungs as much as possible and is then completely immersed in water of density 1000 kg/m

^{3}while suspended from a harness. Her apparent weight is now 21.2 N. What is her density? A)1050 kg/m^{3}B)1040 kg/m^{3}C)1030 kg/m^{3}D)960 kg/m^{3}E)56.1 kg/m^{3}Free

Multiple Choice

Q 84Q 84

The bathyscaphe Trieste consists of a thin-walled but very strong cylindrical hull, 15.2 m long and 3.66 m in diameter, filled with gasoline with a density of 880 kg/m

^{3}to make it buoyant. If it is totally submerged in seawater with a density of 1025 kg/m^{3}and neither rising nor sinking, what is the weight of the Trieste craft? A)127 kN B)227 kN C)327 kN D)427 kN E)527 kNFree

Multiple Choice

Q 85Q 85

A cylinder, semicircular in cross-section, is 10 m long and 5.0 m in radius. It is completely submerged, with its flat bottom side horizontal and 8.0 m below the water surface, as shown in the figure. What is the magnitude of the net force on the curved upper surface of the half-cylinder? Neglect atmospheric pressure.
A)2.0 × 10

^{6}N B)2.5 × 10^{6}N C)3.0 × 10^{6}N D)3.5 × 10^{6}N E)4.0 × 10^{6}NFree

Multiple Choice

Q 86Q 86

A rectangular wooden block measures 10.0 cm × 4.00 cm × 2.00 cm. When the block is placed in water, it floats horizontally, with its bottom face 1.65 cm below the surface. What is the density of the wood? The density of water is 1.00 g/cm

^{3}. A)0.825 g/cm^{3}B)1.21 g/cm^{3}C)1.65 g/cm^{3}D)0.606 g/cm^{3}E)0.350 g/cm^{3}Free

Multiple Choice

Q 87Q 87

Consider a very small hole in the bottom of a tank that is in diameter and filled with water to a height of Find the speed at which the water exits the tank through the hole.
A)4.20 m/s
B)17.64 m/s
C)44.1 m/s
D)48.3 m/s

Free

Multiple Choice

Q 88Q 88

Water flowing through a cylindrical pipe suddenly comes to a section of pipe where the diameter decreases to 86% of its previous value. If the speed of the water in the larger section of the pipe was what is its speed in this smaller section if the water behaves like an ideal incompressible fluid?
A)43 m/s
B)37 m/s
C)28 m/s
D)24 m/s

Free

Multiple Choice

Q 89Q 89

A pump uses a piston of 15 cm diameter that moves at 2.0 cm/s as it pushes a fluid through a pipe. What is the speed of the fluid when it enters a portion of the pipe that is 3.0 mm in diameter? Treat the fluid as ideal and incompressible.
A)50 m/s
B)50 cm/s
C)6.0 cm/s
D)22 cm/s

Free

Multiple Choice

Q 90Q 90

An incompressible ideal fluid flows steadily through a pipe that has a change in diameter. The fluid speed at a location where the pipe diameter is 8.0 cm is 1.28 m/s. What is the fluid speed at a location where the diameter has narrowed to 4.0 cm?
A)0.32 m/s
B)0.64 m/s
C)1.3 m/s
D)2.6 m/s
E)5.1 m/s

Free

Multiple Choice

Q 91Q 91

Fluid flows at 2.0 m/s through a pipe of diameter 3.0 cm. What is the volume flow rate of the fluid?
A)1.4 × 10

^{-3}m^{3}/s B)5.7 × 10^{-3}m^{3}/s C)14 m^{3}/s D)57 m^{3}/sFree

Multiple Choice

Q 92Q 92

Ideal incompressible fluid flows through a 4.0-cm-diameter pipe at 1.0 m/s. There is a 2.0 cm diameter constriction in the line. What is the speed of the fluid in this constriction?
A)0.25 m/s
B)0.50 m/s
C)2.0 m/s
D)4.0 m/s

Free

Multiple Choice

Q 93Q 93

Water, which we can treat as ideal and incompressible, flows at 12 m/s in a horizontal pipe with a pressure of 3.0 × 10

^{4}Pa. If the pipe widens to twice its original radius, what is the pressure in the wider section? A)3.0 × 10^{4}Pa B)4.9 × 10^{4}Pa C)7.4 × 10^{4}Pa D)9.8 × 10^{4}PaFree

Multiple Choice

Q 94Q 94

A hole of radius 1.0 mm forms in the bottom of a very large water storage tank that holds water to a depth of 15 m. At what volume rate will water flow out of the hole?
A)5.4 × 10

^{-4}m^{3}/s B)5.4 × 10^{-5}m^{3}/s C)5.4 × 10^{-6}m^{3}/s D)5.4 × 10^{-7}m^{3}/sFree

Multiple Choice

Q 95Q 95

Ideal incompressible water flows through a horizontal pipe of cross-sectional area 10.0 cm

^{2}at a pressure of 0.250 atm with a volume flow rate of 1.00 × 10^{-3}m^{3}/s. At a valve, the effective cross-sectional area of the pipe is reduced to 5.00 cm^{2}. What is the pressure at the valve? A)0.112 atm B)0.157 atm C)0.200 atm D)0.235 atmFree

Multiple Choice

Q 96Q 96

For a certain patient, the build-up of fatty tissue on the wall of an artery has decreased the arterial radius by 10%. By how much would the pressure provided by the heart have to be increased to maintain a constant volume of blood flow? Model the blood as an ideal incompressible fluid.
A)48%
B)52%
C)46%
D)54%

Free

Multiple Choice

Q 97Q 97

An ideal incompressible fluid flows at 0.252 m/s through a 44-mm diameter cylindrical pipe. The pipe widens to a square cross sectional area that is 5.5 cm on a side. Assume steady flow throughout the system.
(a)What is the speed of the fluid through the square section of pipe?
(b)What is the flow rate in liters per minute?

Free

Essay

Q 98Q 98

Ideal incompressible water is flowing in a drainage channel of rectangular cross-section. At one point, the width of the channel is 12 m, the depth of water is 6.0 m, and the speed of the flow is 2.5 m/s. At a point downstream, the width has narrowed to 9.0 m, and the depth of water is 8.0 m. What is the speed of the flow at the second point?
A)2.0 m/s
B)2.5 m/s
C)3.0 m/s
D)3.5 m/s
E)4.0 m/s

Free

Multiple Choice

Q 99Q 99

Water is flowing in a drainage channel of rectangular cross-section. The width of the channel is 15 m, the depth of water is 8.0 m, and the speed of the flow is 2.5 m/s. What is the mass flow rate of the water? The density of water is 1000 kg/m

^{3}. A)2.0 × 10^{5}kg/s B)2.0 × 10^{3}kg/s C)3.0 × 10^{5}kg/s D)3.0 × 10^{3}kg/s E)3.0 × 10^{2}kg/sFree

Multiple Choice

Q 100Q 100

In a section of horizontal pipe with a diameter of 3.0 cm, the pressure is 100 kPa and water is flowing with a speed of 1.5 m/s. The pipe narrows to 2.0 cm. What is the pressure in the narrower region? Treat the water as an ideal incompressible fluid.
A)95 kPa
B)48 kPa
C)44 kPa
D)230 kPa
E)67 kPa

Free

Multiple Choice

Q 101Q 101

Water flows through a horizontal pipe of cross-sectional area 10.0 cm

^{2}at a pressure of 0.250 atm with a flow rate is 1.00 L/s. At a valve, the effective cross-sectional area of the pipe is reduced to 5.00 cm^{2}. What is the pressure at the valve? The density of water is 1000 kg/m^{3}, and treat it as an ideal incompressible fluid. A)0.110 atm B)0.235 atm C)0.200 atm D)0.157 atm E)7700 PaFree

Multiple Choice

Q 102Q 102

An ideal incompressible fluid flows at 12 m/s in a horizontal pipe. If the pipe widens to twice its original radius, what is the flow speed in the wider section?
A)12 m/s
B)6.0 m/s
C)4.0 m/s
D)3.0 m/s

Free

Multiple Choice

Q 103Q 103

Water flows out of a large reservoir through an open pipe, as shown in the figure. What is the speed of the water as it comes out of the pipe?
A)8.9 m/s
B)9.9 m/s
C)13 m/s
D)14 m/s
E)16 m/s

Free

Multiple Choice

Q 104Q 104

Water flows out of a large reservoir through 5.0-cm diameter pipe. The pipe connects to a 3.0-cm diameter pipe that is open to the atmosphere, as shown in the figure. What is the speed of the water in the 5.0-cm pipe? Treat the water as an ideal incompressible fluid.
A)2.3 m/s
B)3.2 m/s
C)3.9 m/s
D)8.9 m/s
E)10 m/s

Free

Multiple Choice

Q 105Q 105

A pressurized cylindrical tank, 5.0 m in diameter, contains water that emerges from the pipe at point C with a speed of as shown in the figure. Point A is 10 m above point B and point C is 3.0 m above point B. The area of the pipe at point B is and the pipe narrows to an area of at point C. Assume that the water is an ideal fluid in laminar flow. The density of water is 1000 kg/m

^{3}The mass flow rate in the pipe is closest to A)520 Kg/s. B)470 Kg/s. C)420 Kg/s. D)360 Kg/s. E)310 Kg/s.Free

Multiple Choice

Q 106Q 106

A pressurized cylindrical tank, 5.0 m in diameter, contains water that emerges from the pipe at point C with a speed of as shown in the figure. Point A is 10 m above point B and point C is 3.0 m above point B. The area of the pipe at point B is and the pipe narrows to an area of at point C. Assume that the water is an ideal fluid in laminar flow. The density of water is 1000 kg/m

^{3}. The rate at which the water level is falling in the tank is closest to A)300 mm/s. B)340 mm/s. C)250 mm/s. D)210 mm/s. E)160 mm/s.Free

Multiple Choice

Q 107Q 107

As shown in the figure, water (density 1000 kg/ )is flowing in a pipeline. At point 1 the water speed is Point 2 is 5.20 m above point 1. The cross-sectional area of the pipe is 0.0800 at point 1 and at point 2. What is the pressure difference between points 1 and 2? Treat the water as an ideal incompressible fluid.

Free

Essay

Q 108Q 108

A large cylindrical water tank 11.5 m in diameter and 13.5 m tall is supported with its base 8.75 m above the ground by a stand as shown in the figure. The water level in the tank is 10.6 m deep, and the density of the water in the tank is 1.00 g/cm

^{3}. A very small hole is formed at the base of the vertical wall of the tank, and water is squirting out of this hole horizontally. When this water hits the ground, how far has it traveled horizontally from the hole, assuming no air resistance?Free

Essay

Q 109Q 109

Glycerin, with a viscosity of 1.5 N ∙ s/m

^{2}, is flowing with an average speed of 1.2 m/s through a tube that has a radius of 5.0 mm and is 25 cm long. What is the drop in pressure over the length of this pipe? A)140 kPa B)46 kPa C)72 kPa D)76 kPa E)130 kPaFree

Multiple Choice

Q 110Q 110

Motor oil, with a viscosity of 0.25 N ∙ s/m

^{2}, is flowing through a tube that has a radius of 3.0 mm and is 1.0 m long. The drop in pressure over the length of the tube is 200 kPa. What is the average speed of the oil? A)0.80 m/s B)0.90 m/s C)1.0 m/s D)1.1 m/s E)1.2 m/sFree

Multiple Choice

Q 111Q 111

Motor oil, with a viscosity of 0.25 N ∙ s/m

^{2}, is flowing through a tube that has a radius of 5.0 mm and is 25 cm long. The drop in pressure is 300 kPa. What is the volume of oil flowing through the tube per second? A)0.00038 m^{3}/s B)0.025 m^{3}/s C)0.0012 m^{3}/s D)4.7 m^{3}/s E)7.5 m^{3}/sFree

Multiple Choice

Q 112Q 112

A fluid is flowing with an average speed of 1.5 m/s through a tube that has a radius of 2.0 mm and is 18 cm long. The drop in pressure is 967 Pa. What is the viscosity of the fluid?
A)0.0018 N ∙ s/m

^{2}B)0.0056 N ∙ s/m^{2}C)0.028 N ∙ s/m^{2}D)0.013 N ∙ s/m^{2}E)0.0034 N ∙ s/m^{2}Free

Multiple Choice