Question 1

A large block of wood and a small block of iron each register 2000 N on a weighing scale. Taking buoyancy of air into account, which has the greater mass?

Accepted Answer

A) wood 
B) iron 
C) both the same 
A) wood 
B) iron 
C) both the same A

Question 2

As water in a confined pipe speeds up, the pressure it exerts against the inner walls of the pipe

Accepted Answer

A) increases. 
B) decreases. 
C) remains constant if flow rate is constant. 
D) none of the above 
A) increases. 
B) decreases. 
C) remains constant if flow rate is constant. 
D) none of the above B

Question 3

Why will a helium-filled balloon rise in air while an air-filled balloon sinks?

Accepted Answer

Both balloons displace air and have a buoyant force that depends on their volumes. If buoyancy were the only force acting, they both would rise, but there's weight. The air-filled balloon is simply heavier than the air it displaces, thus its weight is greater than the buoyant force, and it sinks. It is heavier because the stretched balloon fabric compresses the air within. Likewise for the helium, but it is so low in density that even when compressed it is still lighter than the air it displaces.

Question 4

A rock suspended by a weighing scale weighs 3 N when submerged in water and 5 N out of water. What is the buoyant force on the rock?

Accepted Answer

A) 8 N 
B) 5 N 
C) 3 N 
D) 2 N 
E) none of the above 
A) 8 N 
B) 5 N 
C) 3 N 
D) 2 N 
E) none of the above

Question 5

A liter-sized block of ordinary wood floats in water. The volume of water displaced is

Accepted Answer

A) less than 1 L. 
B) 1 L. 
C) more than 1 L. 
D) none of the above 
A) less than 1 L. 
B) 1 L. 
C) more than 1 L. 
D) none of the above

Question 6

If a battleship sinks in a canal lock, the water level in the lock

Accepted Answer

A) rises. 
B) falls. 
C) remains unchanged. 
A) rises. 
B) falls. 
C) remains unchanged.

Question 7

When a chocolate bar is cut in half, its density is

Accepted Answer

A) halved. 
B) unchanged. 
C) doubled. 
A) halved. 
B) unchanged. 
C) doubled.

Question 8

Airplane lift is achieved when air pressure on the bottom of a wing is

Accepted Answer

A) greater than pressure on top. 
B) less than pressure on top. 
C) the same as pressure on top. 
A) greater than pressure on top. 
B) less than pressure on top. 
C) the same as pressure on top.

Question 9

There is a legend of a Dutch boy who bravely held back the Atlantic Ocean by plugging a leak near the top of a dike with his finger until help arrived. Which of the following is most likely?

Accepted Answer

A) the huge size of the Atlantic Ocean makes this impossible 
B) force on his finger would be huge but pressure small enough 
C) the force on his finger would have been less than 1 N 
D) both the force and pressure on his finger would have been huge, but not too huge for a public-spirited Dutch lad 
E) none of the above 
A) the huge size of the Atlantic Ocean makes this impossible 
B) force on his finger would be huge but pressure small enough 
C) the force on his finger would have been less than 1 N 
D) both the force and pressure on his finger would have been huge, but not too huge for a public-spirited Dutch lad 
E) none of the above

Question 10

The volume of water displaced by a floating 20-ton boat is

Accepted Answer

A) 20 cubic meters. 
B) the volume of 20 tons of water. 
C) the volume of the boat. 
D) depends on the shape of the ship's hull. 
E) none of the above 
A) 20 cubic meters. 
B) the volume of 20 tons of water. 
C) the volume of the boat. 
D) depends on the shape of the ship's hull. 
E) none of the above

Question 11

A barometer can be made with water. Compared with a mercury barometer, the column height for a water barometer would be

Accepted Answer

A) shorter. 
B) the same. 
C) higher. 
A) shorter. 
B) the same. 
C) higher.

Question 12

What is the buoyant force acting on a 10-ton ship floating in a fresh-water lake?

Accepted Answer

A) less than 10 tons 
B) 10 tons 
C) more than 10 tons 
D) not enough information 
A) less than 10 tons 
B) 10 tons 
C) more than 10 tons 
D) not enough information

Question 13

When a 5-N block of wood floats in mercury the buoyant force on it is

Accepted Answer

A) less than 5 N. 
B) 5 N. 
C) more than 5 N. 
A) less than 5 N. 
B) 5 N. 
C) more than 5 N.

Question 14

What is the weight of water displaced by a 100-ton floating ship?

Accepted Answer

A) less than 100 tons 
B) 100 tons 
C) more than 100 tons 
D) 100 cubic meters 
E) depends on the ship's shape 
A) less than 100 tons 
B) 100 tons 
C) more than 100 tons 
D) 100 cubic meters 
E) depends on the ship's shape

Question 15

A hydraulic device has two pistons, one with a small cross-section area and another piston with a larger cross-section area. If a given force is applied to the small piston, the output force on the larger-area piston will be

Accepted Answer

A) less. 
B) the same. 
C) more. 
D) all of the above 
E) none of the above 
A) less. 
B) the same. 
C) more. 
D) all of the above 
E) none of the above

Question 16

Wood from the Lignum vitae tree in South America is denser than water. Could a boat be made with this wood? A raft? Briefly explain.

Accepted Answer

Yes, a boat could easily be made of this

Question 17

What is the approximate density of a fish, compared with the density of water? Defend your answer.

Accepted Answer

The density of a fish is the same as the

Question 18

Two life preservers have identical volumes, one filled with Styrofoam and the other filled with sand. When both life preservers are fully submerged, the buoyant force is greater on the one filled with

Accepted Answer

A) Styrofoam. 
B) sand. 
C) same on each if volumes remain the same. 
A) Styrofoam. 
B) sand. 
C) same on each if volumes remain the same.

Question 19

When gas in a container expands to twice its volume at constant temperature, the gas pressure

Accepted Answer

A) is half. 
B) doubles. 
C) quadruples. 
D) remains the same. 
A) is half. 
B) doubles. 
C) quadruples. 
D) remains the same.

Question 20

A rising balloon is buoyed up with a force equal to the

Accepted Answer

A) weight of air it displaces. 
B) density of surrounding air. 
C) atmospheric pressure. 
D) weight of the balloon and its contents. 
E) all of the above 
A) weight of air it displaces. 
B) density of surrounding air. 
C) atmospheric pressure. 
D) weight of the balloon and its contents. 
E) all of the above

Exam 5: Fluid Mechanics

A large block of wood and a small block of iron each register 2000 N on a weighing scale. Taking buoyancy of air into account, which has the greater mass?

As water in a confined pipe speeds up, the pressure it exerts against the inner walls of the pipe

Why will a helium-filled balloon rise in air while an air-filled balloon sinks?

A rock suspended by a weighing scale weighs 3 N when submerged in water and 5 N out of water. What is the buoyant force on the rock?

A liter-sized block of ordinary wood floats in water. The volume of water displaced is

If a battleship sinks in a canal lock, the water level in the lock

When a chocolate bar is cut in half, its density is

Airplane lift is achieved when air pressure on the bottom of a wing is

There is a legend of a Dutch boy who bravely held back the Atlantic Ocean by plugging a leak near the top of a dike with his finger until help arrived. Which of the following is most likely?

The volume of water displaced by a floating 20-ton boat is

A barometer can be made with water. Compared with a mercury barometer, the column height for a water barometer would be

What is the buoyant force acting on a 10-ton ship floating in a fresh-water lake?

When a 5-N block of wood floats in mercury the buoyant force on it is

What is the weight of water displaced by a 100-ton floating ship?

A hydraulic device has two pistons, one with a small cross-section area and another piston with a larger cross-section area. If a given force is applied to the small piston, the output force on the larger-area piston will be

Wood from the Lignum vitae tree in South America is denser than water. Could a boat be made with this wood? A raft? Briefly explain.

What is the approximate density of a fish, compared with the density of water? Defend your answer.

Two life preservers have identical volumes, one filled with Styrofoam and the other filled with sand. When both life preservers are fully submerged, the buoyant force is greater on the one filled with

When gas in a container expands to twice its volume at constant temperature, the gas pressure

A rising balloon is buoyed up with a force equal to the

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: the Nature of Science

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