Question 1

In a collision between a huge SUV and a small compact car,the SUV exerts a larger force on the compact than the compact exerts on the SUV.

Accepted Answer

A) True 
 B)False

Question 2

Suppose you are playing hockey on a new-age ice surface in which there is no friction between the ice and the hockey puck.You wind up and hit the puck as hard as you can.Just after the puck loses contact with your stick,the puck

Accepted Answer

A) will not slow down or speed up. 
B) will start to slow down. 
C) will speed up a little,and then slow down. 
D) will speed up a little,and then move at a constant speed. 
A) will not slow down or speed up. 
B) will start to slow down. 
C) will speed up a little,and then slow down. 
D) will speed up a little,and then move at a constant speed.

Question 3

The figure shows an object's acceleration-versus-force graph.What is the object's mass in grams?

Accepted Answer

A) 2.5 
B) 1.6 
C) 630 
D) 400,000 
A) 2.5 
B) 1.6 
C) 630 
D) 400,000

Question 4

An object is moving with a constant velocity.Which statement(s)MUST be true?

Accepted Answer

A) The net force on the object is zero. 
B) A small net force is acting on the object,in the direction of motion. 
C) No forces are acting on the object. 
D) Two of the above statements are true. 
A) The net force on the object is zero. 
B) A small net force is acting on the object,in the direction of motion. 
C) No forces are acting on the object. 
D) Two of the above statements are true.

Question 5

In order to get an object moving,you must push harder on it than it pushes back on you.

Accepted Answer

A) True 
 B)False

Question 6

Three children pull on a toy in three different directions,yet the toy does not move.Explain how this could be possible.

Accepted Answer

As long as the vector sum of a

Question 7

If you pound a feather with a hammer,the feather always pushes on the hammer just as hard as the hammer pushes on the feather.

Accepted Answer

A) True 
 B)False

Question 8

Consider what happens when you jump up in the air.Which of the following is the most accurate statement?

Accepted Answer

A) It is the upward force exerted by the ground that pushes you up,but this force can never exceed your weight. 
B) You are able to spring up because the earth exerts a force upward on you which is stronger than the downward force you exert on the earth. 
C) Since the ground is stationary,it cannot exert the upward force necessary to propel you into the air.Instead,it is the internal forces of your muscles acting on your body itself which propels the body into the air. 
D) When you push down on the earth with a force greater than your weight,the earth will push back with the same magnitude force and thus propel you into the air. 
A) It is the upward force exerted by the ground that pushes you up,but this force can never exceed your weight. 
B) You are able to spring up because the earth exerts a force upward on you which is stronger than the downward force you exert on the earth. 
C) Since the ground is stationary,it cannot exert the upward force necessary to propel you into the air.Instead,it is the internal forces of your muscles acting on your body itself which propels the body into the air. 
D) When you push down on the earth with a force greater than your weight,the earth will push back with the same magnitude force and thus propel you into the air.

Question 9

The figure shows an acceleration-versus-force graph for three objects pulled by rubber bands.The mass of object 2 is 36 kg.What are the masses of objects 1 and 3?

Accepted Answer

A) 14 kg and 90 kg 
B) 72 kg and 18 kg 
C) 90 kg and 18 kg 
D) 14 kg and 72 kg 
A) 14 kg and 90 kg 
B) 72 kg and 18 kg 
C) 90 kg and 18 kg 
D) 14 kg and 72 kg

Question 10

Explain,in terms of Newton's Laws,why a quick jerk on a string may cause it to break,while the same change in momentum performed over a longer time will not.

Accepted Answer

Since F = @#IMG-DLM& ,for a given moment

Question 11

Two children fighting over a toy pull on the toy in different directions.One child pulls to the north with a force of 5.3 N,and the other child pulls to the east with a force of 6.3 N.What is the magnitude of the net force on the toy?

Accepted Answer

A) 8.2 N 
B) 12 N 
C) 1.0 N 
D) 9.3 N 
A) 8.2 N 
B) 12 N 
C) 1.0 N 
D) 9.3 N

Question 12

A woman is straining to lift a large crate,without success.It is too heavy.We denote the forces on the crate as follows: P is the upward force being exerted on the crate by the person,C is the contact force on the crate by the floor,and W is the weight of the crate.   How are the magnitudes of these forces related,while the person is trying unsuccessfully to lift the crate?

Accepted Answer

A) P + C = W 
B) P + C  W 
D) P = C 
A) P + C = W 
B) P + C  W 
D) P = C

Question 13

An elevator suspended by a vertical cable is moving downward but slowing down.The tension in the cable must be greater than the weight of the elevator.

Accepted Answer

A) True 
 B)False

Question 14

A large truck collides head-on with a cyclist.During the collision

Accepted Answer

A) the truck exerts the same amount of force on the cyclist as the cyclist exerts on the truck. 
B) the truck exerts a greater amount of force on the cyclist than the cyclist exerts on the truck. 
C) the truck exerts a smaller amount of force on the cyclist than the cyclist exerts on the truck. 
D) the truck exerts a force on the cyclist,but the cyclist exerts no force on the truck. 
A) the truck exerts the same amount of force on the cyclist as the cyclist exerts on the truck. 
B) the truck exerts a greater amount of force on the cyclist than the cyclist exerts on the truck. 
C) the truck exerts a smaller amount of force on the cyclist than the cyclist exerts on the truck. 
D) the truck exerts a force on the cyclist,but the cyclist exerts no force on the truck.

Question 15

A box is placed on a table which rests on the floor.The box pushes on the table;the reaction force to the box's push on the table is the table's push on the floor.

Accepted Answer

A) True 
 B)False

Question 16

If the rockets of a spaceship in outer space (far from all gravity)suddenly lose power and go off,the spaceship will gradually slow to a stop.

Accepted Answer

A) True 
 B)False

Question 17

Your younger brother is supposed to mow the lawn using a push mower.He reasons from Newton's Third Law that the mower will push back with the same force he exerts on the mower;therefore nothing will move and attempting to mow the lawn is pointless.What is wrong with his reasoning?

Accepted Answer

The boy exerts a force on the

Question 18

Bill and Susan are both standing on identical skateboards (with really good ball bearings),initially at rest.Bill weighs three times as much as Susan.Bill pushes horizontally on Susan's back,causing Susan to start moving away from Bill.Immediately after Bill stops pushing,

Accepted Answer

A) Susan and Bill are moving away from each other,and Susan's speed is three times that of Bill. 
B) Susan is moving away from Bill,and Bill is stationary. 
C) Susan and Bill are moving away from each other,with equal speeds. 
D) Susan and Bill are moving away from each other,and Susan's speed is three times less than that of Bill. 
A) Susan and Bill are moving away from each other,and Susan's speed is three times that of Bill. 
B) Susan is moving away from Bill,and Bill is stationary. 
C) Susan and Bill are moving away from each other,with equal speeds. 
D) Susan and Bill are moving away from each other,and Susan's speed is three times less than that of Bill.

Question 19

The figure shows two forces of equal magnitude acting on an object.If the common magnitude of the forces is 4.6 N and the angle between them is 40°,what third force will cause the object to be in equilibrium?

Accepted Answer

A) 8.6 N pointing to the right 
B) 7.0 N pointing to the right 
C) 4.3 N pointing to the right 
D) 3.5 N pointing to the right 
A) 8.6 N pointing to the right 
B) 7.0 N pointing to the right 
C) 4.3 N pointing to the right 
D) 3.5 N pointing to the right

Question 20

When decelerating quickly in a car,you feel as if you are being thrown forward in your seat.Which one of Newton's Laws most directly explains this effect? Explain your reasoning.

Accepted Answer

Newton's First Law is the best choice.Yo

Exam 4: Forces and Newtons Laws of Motion

In a collision between a huge SUV and a small compact car,the SUV exerts a larger force on the compact than the compact exerts on the SUV.

Suppose you are playing hockey on a new-age ice surface in which there is no friction between the ice and the hockey puck.You wind up and hit the puck as hard as you can.Just after the puck loses contact with your stick,the puck

The figure shows an object's acceleration-versus-force graph.What is the object's mass in grams?

An object is moving with a constant velocity.Which statement(s)MUST be true?

In order to get an object moving,you must push harder on it than it pushes back on you.

Three children pull on a toy in three different directions,yet the toy does not move.Explain how this could be possible.

If you pound a feather with a hammer,the feather always pushes on the hammer just as hard as the hammer pushes on the feather.

Consider what happens when you jump up in the air.Which of the following is the most accurate statement?

The figure shows an acceleration-versus-force graph for three objects pulled by rubber bands.The mass of object 2 is 36 kg.What are the masses of objects 1 and 3?

Explain,in terms of Newton's Laws,why a quick jerk on a string may cause it to break,while the same change in momentum performed over a longer time will not.

Two children fighting over a toy pull on the toy in different directions.One child pulls to the north with a force of 5.3 N,and the other child pulls to the east with a force of 6.3 N.What is the magnitude of the net force on the toy?

An elevator suspended by a vertical cable is moving downward but slowing down.The tension in the cable must be greater than the weight of the elevator.

A large truck collides head-on with a cyclist.During the collision

A box is placed on a table which rests on the floor.The box pushes on the table;the reaction force to the box's push on the table is the table's push on the floor.

If the rockets of a spaceship in outer space (far from all gravity)suddenly lose power and go off,the spaceship will gradually slow to a stop.

Your younger brother is supposed to mow the lawn using a push mower.He reasons from Newton's Third Law that the mower will push back with the same force he exerts on the mower;therefore nothing will move and attempting to mow the lawn is pointless.What is wrong with his reasoning?

Bill and Susan are both standing on identical skateboards (with really good ball bearings),initially at rest.Bill weighs three times as much as Susan.Bill pushes horizontally on Susan's back,causing Susan to start moving away from Bill.Immediately after Bill stops pushing,

The figure shows two forces of equal magnitude acting on an object.If the common magnitude of the forces is 4.6 N and the angle between them is 40°,what third force will cause the object to be in equilibrium?

When decelerating quickly in a car,you feel as if you are being thrown forward in your seat.Which one of Newton's Laws most directly explains this effect? Explain your reasoning.

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Applying Newtons Laws

Circular Motion,orbits,and Gravity

Rotational Motion

Equilibrium and Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Current and Resistance

Circuits

Magnetic Fields and Forces

Electromagnetic Induction and Electromagnetic Waves

Ac Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

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