Question 1

A venturi tube may be used as the inlet to an automobile carburetor.If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter,what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (ρ = 1.2 kg/m3. )

Accepted Answer

A) 70 Pa 
B) 85 Pa 
C) 100 Pa 
D) 120 Pa 
E) 81 Pa

Question 2

A supertanker filled with oil has a total mass of 6.1 × 108 kg.If the dimensions of the ship are those of a rectangular box 300 meters long,80 meters wide,and 40 meters high,determine how far the bottom of the ship is below sea level.(ρsea = 1 020 kg/m3. )

Accepted Answer

A) 10 m 
B) 15 m 
C) 20 m 
D) 25 m 
E) 30 m

Question 3

A wood block is placed on top of the ice in a large bowl half full of ice.The bowl is then filled to the brim with water,with the wood block riding on top of the ice.As the ice melts,

Accepted Answer

A) the density of the water decreases. 
B) the water level falls below the rim. 
C) the water level rises and water spills out of the bowl. 
D) the water level does not change. 
E) the wood block descends,causing water to spill out of the bowl.

Question 4

Water pressurized to 3.5 × 105 Pa is flowing at 5.0 m/s in a horizontal pipe which contracts to 1/3 its former area.What are the pressure and velocity of the water after the contraction?

Accepted Answer

A) 2.5 × 105 Pa,15 m/s 
B) 3.0 × 105 Pa,10 m/s 
C) 3.0 × 105 Pa,15 m/s 
D) 4.5 × 105 Pa,1.5 m/s 
E) 5.5 × 105 Pa,1.5 m/s

Question 5

A vertical pipe,closed at the bottom end,is filled to a depth of 1.00 m with water and then an amount of oil of density  
is added to make the total depth 2.00 m.The oil and water don't mix with the oil floating on top of the water.What is the increase in pressure at the bottom end of the pipe as a result of adding the fluids?

Accepted Answer

The answer of A vertical pipe,closed at the bottom end,is...

Question 6

A waiter in a restaurant fills a pitcher full of water and ice so that water would spill out if any more were added.As the ice starts to melt

Accepted Answer

A) the water level in the pitcher falls. 
B) the water level in the pitcher remains the same. 
C) water starts to flow out the spout of the pitcher. 
D) the pressure on the bottom of the pitcher decreases. 
E) the pressure on the bottom of the pitcher increases.

Question 7

An empty spice bottle has an inner volume of 1.31 × 10−4 m3.It has a mass of 112 g when filled with air,and it displaces 1.63 × 10−4 m3 of water when fully submerged.What volume of mercury (ρHg = 13.6 × 103 kg/m3)must be added to the empty bottle so that it will just submerge?

Accepted Answer

A) 3.75 cm3 
B) 12.0 cm3 
C) 101 cm3 
D) 147 cm3 
E) 237 cm3

Question 8

One hundred milliliters of water is poured into a U-tube that has a cross-sectional area of 1 cm².Then 100 milliliters of oil,with a density 80% that of water,is poured down one side of the U-tube so that the oil floats on the water.Find the difference in height of the liquid surfaces on the two sides of the U-tube.

Accepted Answer

The answer of One hundred milliliters of water is poured...

Question 9

Find the average density of a red giant star with a mass of 20 × 1030 kg (approximately 10 solar masses)and a radius of 150 × 109 m (equal to the Earth's distance from the sun).

Accepted Answer

A) 1.41 × 10−4 kg/m3 
B) 0.007 kg/m3 
C) 1.41 kg/m3 
D) 710 kg/m3 
E) 1.41 × 10−3 kg/m3

Question 10

The water level in a reservoir is maintained at a constant level.What is the exit velocity in an outlet pipe 3.0 m below the water surface?

Accepted Answer

A) 2.4 m/s 
B) 3.0 m/s 
C) 5.4 m/s 
D) 7.7 m/s 
E) 49 m/s

Question 11

What is the total mass of the Earth's atmosphere? The radius of the Earth is 6.4 × 106 m,and 1 ATM = 1.01 × 105 N/m2.

Accepted Answer

A) 5.3 × 1016 kg 
B) 1.1 × 1018 kg 
C) 5.3 × 1018 kg 
D) 1.1 × 1020 kg 
E) 5.3 × 109 kg

Question 12

Two identical fish,both at sea level,float in two identical aquariums with identical quantities of water.Fish A is in Alaska,so it weighs more than fish B at the equator,since g is larger at sea level in Alaska.Which statement is correct?

Accepted Answer

A) A comparison is impossible unless they are both floating at the same level. 
B) Fish A displaces a greater quantity of water than fish B. 
C) Fish B displaces a greater quantity of water than fish A. 
D) They both displace the same quantity of water. 
E) Fish A has a smaller acceleration than Fish B when equal horizontal forces are applied to each,because Fish A weighs more.

Question 13

A blimp is filled with 200 m3 of helium.How much mass can the balloon lift? The density of helium is one-seventh that of air,and the density of air is 1/800 that of water.Consider the mass of the balloon to be negligible.

Accepted Answer

A) 115 kg 
B) 214 kg 
C) 315 kg 
D) 415 kg 
E) 37 kg

Question 14

A natural gas pipeline with a diameter 0.250 m delivers 1.55 cubic meters of gas per second.What is the flow speed of the gas in the pipeline?

Accepted Answer

The answer of A natural gas pipeline with a diameter...

Question 15

A stonecutter's chisel has an edge area of 0.7 cm2.If the chisel is struck with a force of 42 N,what is the pressure exerted on the stone?

Accepted Answer

A) 600 N/m2 
B) 30 000 N/m2 
C) 300 000 N/m2 
D) 600 000 N/m2 
E) 6 000 N/m2

Question 16

A hole is punched in a full milk carton,10 cm below the top.What is the initial velocity of outflow?

Accepted Answer

A) 1.4 m/s 
B) 2.0 m/s 
C) 2.8 m/s 
D) 3.9 m/s 
E) 4.2 m/s

Question 17

A hose has been clamped so that the area at the clamp is only one quarter the area of the rest of the hose.When we ignore the viscosity of water,the ratio of the speed of the water through the clamped area to the speed of the water when it leaves the hose is

Accepted Answer

A)   . 
B)   . 
C) 1. 
D) 2 
E) 4.

Question 18

An iron block of density ρFe and of volume l3 is immersed in a fluid of density ρfluid.The block hangs from a scale which reads W as the weight.The top of the block is a height h below the surface of the fluid.The correct equation for the reading of the scale is

Accepted Answer

A) W = (ρFe − ρfluid)ghl2. 
B) W = (ρfluid − ρFe)gl3. 
C) W = (ρFe − ρfluid)gl3. 
D) W = (ρFe + ρfluid)ghl2. 
E) W = (ρFe + ρfluid)gl3.

Question 19

Find the average density of a white dwarf star if it has a mass equal to that of the sun (2.0 × 1030 kg)and a radius equal to that of the Earth (6.4 × 106 m).

Accepted Answer

A) 9.0 × 106 kg/m3 
B) 1.8 × 107 kg/m3 
C) 1.8 × 109 kg/m3 
D) 3.6 × 1010 kg/m3 
E) 9.0 × 107 kg/m3

Question 20

Melanie says that when a diver enters an underwater cave of height h,the pressure on her is no greater than ρWgh.Rosalind says that if the bottom of the cave is a distance H below the water surface,the pressure on the soles of the diver's feet can reach ρWgH.Which one,if either,is correct? (The density of water is ρW. )

Accepted Answer

A) Melanie,because the roof of the cave absorbs the water pressure from above. 
B) Melanie,because only the fluid directly above any volume of the fluid can contribute to the pressure on that volume. 
C) Rosalind,because a fluid exerts equal pressure in all directions at a given depth. 
D) Rosalind,because the pressure also depends on the density,ρc,of the material above the cave roof,so that p = ρcg(H − h)+ ρWgh. 
E) Melanie,because the pressure equals p = ρWgH − ρcg(H − h).

Exam 14: Fluid Mechanics

A venturi tube may be used as the inlet to an automobile carburetor.If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter,what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (ρ = 1.2 kg/m³. )

A supertanker filled with oil has a total mass of 6.1 × 10⁸ kg.If the dimensions of the ship are those of a rectangular box 300 meters long,80 meters wide,and 40 meters high,determine how far the bottom of the ship is below sea level.(ρ_sea = 1 020 kg/m³. )

A wood block is placed on top of the ice in a large bowl half full of ice.The bowl is then filled to the brim with water,with the wood block riding on top of the ice.As the ice melts,

Water pressurized to 3.5 × 10⁵ Pa is flowing at 5.0 m/s in a horizontal pipe which contracts to 1/3 its former area.What are the pressure and velocity of the water after the contraction?

A waiter in a restaurant fills a pitcher full of water and ice so that water would spill out if any more were added.As the ice starts to melt

An empty spice bottle has an inner volume of 1.31 × 10−⁴ m³.It has a mass of 112 g when filled with air,and it displaces 1.63 × 10−⁴ m³ of water when fully submerged.What volume of mercury (ρ_Hg = 13.6 × 10³ kg/m³) must be added to the empty bottle so that it will just submerge?

Find the average density of a red giant star with a mass of 20 × 10³⁰ kg (approximately 10 solar masses) and a radius of 150 × 10⁹ m (equal to the Earth's distance from the sun) .

The water level in a reservoir is maintained at a constant level.What is the exit velocity in an outlet pipe 3.0 m below the water surface?

What is the total mass of the Earth's atmosphere? The radius of the Earth is 6.4 × 10⁶ m,and 1 ATM = 1.01 × 10⁵ N/m².

Two identical fish,both at sea level,float in two identical aquariums with identical quantities of water.Fish A is in Alaska,so it weighs more than fish B at the equator,since g is larger at sea level in Alaska.Which statement is correct?

A blimp is filled with 200 m³ of helium.How much mass can the balloon lift? The density of helium is one-seventh that of air,and the density of air is 1/800 that of water.Consider the mass of the balloon to be negligible.

A natural gas pipeline with a diameter 0.250 m delivers 1.55 cubic meters of gas per second.What is the flow speed of the gas in the pipeline?

A stonecutter's chisel has an edge area of 0.7 cm².If the chisel is struck with a force of 42 N,what is the pressure exerted on the stone?

A hole is punched in a full milk carton,10 cm below the top.What is the initial velocity of outflow?

A hose has been clamped so that the area at the clamp is only one quarter the area of the rest of the hose.When we ignore the viscosity of water,the ratio of the speed of the water through the clamped area to the speed of the water when it leaves the hose is

An iron block of density ρ_Fe and of volume l³ is immersed in a fluid of density ρ_fluid.The block hangs from a scale which reads W as the weight.The top of the block is a height h below the surface of the fluid.The correct equation for the reading of the scale is

Find the average density of a white dwarf star if it has a mass equal to that of the sun (2.0 × 10³⁰ kg) and a radius equal to that of the Earth (6.4 × 10⁶ m) .

Exam 14: Fluid Mechanics

A venturi tube may be used as the inlet to an automobile carburetor.If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter,what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (ρ = 1.2 kg/m3. )

A supertanker filled with oil has a total mass of 6.1 × 108 kg.If the dimensions of the ship are those of a rectangular box 300 meters long,80 meters wide,and 40 meters high,determine how far the bottom of the ship is below sea level.(ρsea = 1 020 kg/m3. )

A wood block is placed on top of the ice in a large bowl half full of ice.The bowl is then filled to the brim with water,with the wood block riding on top of the ice.As the ice melts,

Water pressurized to 3.5 × 105 Pa is flowing at 5.0 m/s in a horizontal pipe which contracts to 1/3 its former area.What are the pressure and velocity of the water after the contraction?

A waiter in a restaurant fills a pitcher full of water and ice so that water would spill out if any more were added.As the ice starts to melt

An empty spice bottle has an inner volume of 1.31 × 10−4 m3.It has a mass of 112 g when filled with air,and it displaces 1.63 × 10−4 m3 of water when fully submerged.What volume of mercury (ρHg = 13.6 × 103 kg/m3) must be added to the empty bottle so that it will just submerge?

Find the average density of a red giant star with a mass of 20 × 1030 kg (approximately 10 solar masses) and a radius of 150 × 109 m (equal to the Earth's distance from the sun) .

The water level in a reservoir is maintained at a constant level.What is the exit velocity in an outlet pipe 3.0 m below the water surface?

What is the total mass of the Earth's atmosphere? The radius of the Earth is 6.4 × 106 m,and 1 ATM = 1.01 × 105 N/m2.

Two identical fish,both at sea level,float in two identical aquariums with identical quantities of water.Fish A is in Alaska,so it weighs more than fish B at the equator,since g is larger at sea level in Alaska.Which statement is correct?

A blimp is filled with 200 m3 of helium.How much mass can the balloon lift? The density of helium is one-seventh that of air,and the density of air is 1/800 that of water.Consider the mass of the balloon to be negligible.

A natural gas pipeline with a diameter 0.250 m delivers 1.55 cubic meters of gas per second.What is the flow speed of the gas in the pipeline?

A stonecutter's chisel has an edge area of 0.7 cm2.If the chisel is struck with a force of 42 N,what is the pressure exerted on the stone?

A hole is punched in a full milk carton,10 cm below the top.What is the initial velocity of outflow?

A hose has been clamped so that the area at the clamp is only one quarter the area of the rest of the hose.When we ignore the viscosity of water,the ratio of the speed of the water through the clamped area to the speed of the water when it leaves the hose is

An iron block of density ρFe and of volume l3 is immersed in a fluid of density ρfluid.The block hangs from a scale which reads W as the weight.The top of the block is a height h below the surface of the fluid.The correct equation for the reading of the scale is

Find the average density of a white dwarf star if it has a mass equal to that of the sun (2.0 × 1030 kg) and a radius equal to that of the Earth (6.4 × 106 m) .

A venturi tube may be used as the inlet to an automobile carburetor.If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter,what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (ρ = 1.2 kg/m³. )

A supertanker filled with oil has a total mass of 6.1 × 10⁸ kg.If the dimensions of the ship are those of a rectangular box 300 meters long,80 meters wide,and 40 meters high,determine how far the bottom of the ship is below sea level.(ρ_sea = 1 020 kg/m³. )

Water pressurized to 3.5 × 10⁵ Pa is flowing at 5.0 m/s in a horizontal pipe which contracts to 1/3 its former area.What are the pressure and velocity of the water after the contraction?

An empty spice bottle has an inner volume of 1.31 × 10−⁴ m³.It has a mass of 112 g when filled with air,and it displaces 1.63 × 10−⁴ m³ of water when fully submerged.What volume of mercury (ρ_Hg = 13.6 × 10³ kg/m³) must be added to the empty bottle so that it will just submerge?

Find the average density of a red giant star with a mass of 20 × 10³⁰ kg (approximately 10 solar masses) and a radius of 150 × 10⁹ m (equal to the Earth's distance from the sun) .

What is the total mass of the Earth's atmosphere? The radius of the Earth is 6.4 × 10⁶ m,and 1 ATM = 1.01 × 10⁵ N/m².

A blimp is filled with 200 m³ of helium.How much mass can the balloon lift? The density of helium is one-seventh that of air,and the density of air is 1/800 that of water.Consider the mass of the balloon to be negligible.

A stonecutter's chisel has an edge area of 0.7 cm².If the chisel is struck with a force of 42 N,what is the pressure exerted on the stone?

An iron block of density ρ_Fe and of volume l³ is immersed in a fluid of density ρ_fluid.The block hangs from a scale which reads W as the weight.The top of the block is a height h below the surface of the fluid.The correct equation for the reading of the scale is

Find the average density of a white dwarf star if it has a mass equal to that of the sun (2.0 × 10³⁰ kg) and a radius equal to that of the Earth (6.4 × 10⁶ m) .