Question 1

For an action force,there must be a reaction force that
A)always acts in the same direction.
B)is slightly smaller in magnitude than the action force.
C)is slightly larger in amplitude than the action force.
D)is exactly equal in magnitude.

Accepted Answer

According to Newton's third law of motion, for every action force (an object pushing or pulling on another object), there is an equal and opposite reaction force (the second object pushing or pulling back with the same amount of force). Therefore, the reaction force has the same magnitude as the action force, but acts in the opposite direction.

Question 2

As a ball falls,the action force is the pull of Earth on the ball.The reaction force is the
A)air resistance acting against the ball.
B)acceleration of the ball.
C)pull of the ball's mass on the Earth.
D)none of these

Accepted Answer

The reaction force to the action force of the pull of Earth on the ball is the pull of the ball's mass on the Earth. This is known as Newton's third law of motion. Air resistance and acceleration are not directly related to the forces acting on the ball in this scenario.

Question 3

A baseball player bats a ball with a force of 1000 N.The reaction force that the ball exerts against the bat is
A)less than 1000 N.
B)more than 1000 N.
C)1000 N.
D)impossible to determine.

Accepted Answer

According to Newton's third law of motion, every action has an equal and opposite reaction. Therefore, the ball exerts a reaction force of 1000 N against the bat.

Question 4

A karate chop delivers a blow of 3000 N to a board that breaks.The force that acts on the hand during this event is
A)zero.
B)1500 N.
C)3000 N.
D)6000 N.

Accepted Answer

According to Newton's Third Law, for every action there is an equal and opposite reaction. In this case, the board exerts a force of 3000 N on the karate chop, and therefore the karate chop exerts an equal and opposite force of 3000 N on the board. The force that acts on the hand is also 3000 N, as it is the force required to break the board. Therefore, the correct answer is C) 3000 N.

Question 5

A Mack truck and a Volkswagen traveling at the same speed have a head-on collision.The vehicle that undergoes the greatest change in velocity will be the
A)Volkswagen.
B)Mack truck.
C)same for both.

Accepted Answer

According to the law of conservation of momentum, the total momentum of the system before the collision is equal to the total momentum after the collision. Since the masses of the two vehicles are different, their velocities after the collision will also be different. The Volkswagen, being the lighter vehicle, will experience a greater change in velocity than the Mack truck. Thus, the Volkswagen will undergo the greatest change in velocity.

Question 6

A automobile and a baby carriage traveling at the same speed collide head-on.The impact force is
A)greater on the automobile.
B)greater on the baby carriage.
C)the same for both.

Accepted Answer

Both the automobile and the baby carriage are traveling at the same speed, so the impact force experienced by them will be equal. This is supported by Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. Therefore, the impact force exerted on the automobile by the baby carriage will be equal in magnitude and opposite in direction to the impact force exerted on the baby carriage by the automobile.

Question 7

A car traveling at 100 km/hr strikes an unfortunate bug and splatters it.The force of impact is
A)greater on the bug.
B)greater on the car.
C)the same for both.

Accepted Answer

According to Newton's third law of motion, for every action, there is an equal and opposite reaction. Therefore, the force of impact on the bug and car would be the same. Even though the car is much larger and more massive than the bug, the bug would experience the same force as the car because the force is distributed over the area of impact.

Question 8

A person is attracted toward the center of Earth by a 500-N gravitational force.The Earth is attracted toward the person with a force of
A)zero.
B)250 N.
C)500 N.
D)1000 N.

Accepted Answer

According to Newton's third law of motion, every action has an equal and opposite reaction. Therefore, the Earth is attracted toward the person with the same force of 500 N.

Question 9

An archer shoots an arrow.Consider the action force to be the bowstring against the arrow.The reaction to this force is the
A)combined weight of the arrow and bowstring.
B)air resistance against the bow.
C)friction of the ground against the archer's feet.
D)grip of the archer's hand on the bow.
E)arrow's push against the bowstring.

Accepted Answer

According to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. In this case, the action force is the bowstring pushing against the arrow, and the reaction force is the arrow pushing back against the bowstring. Therefore, the best choice would be E, the arrow's push against the bowstring.

Question 10

Use the following figure to answer the question: 
-Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war.The greater force on the rope is exerted by
A)Arnold,of course.
B)Suzie,surprisingly.
C)both the same,interestingly enough.

Accepted Answer

Since the rope is massless, the tension in the rope is the same throughout. Therefore, both Arnold and Suzie are exerting the same amount of force on the rope, making choice C the correct answer.

Question 11

A skydiver falls towards the Earth.The attraction of the Earth on the diver pulls the diver down.What is the reaction to this force?
A)air resistance the diver encounters while falling
B)water resistance that will soon act upward on the diver
C)the attraction to the planets,stars,and every particle in the universe
D)all of these
E)none of these

Accepted Answer

According to Newton's third law, the reaction force to the Earth's gravitational pull on the skydiver is the gravitational pull of the skydiver on the Earth.

Question 12

Earth pulls on the moon.Similarly the moon pulls on Earth,evidence that
A)these two pulls comprise an action-reaction pair.
B)Earth is larger so its pull is larger.
C)the moon is smaller so its pull is smaller.
D)larger objects pull harder.

Accepted Answer

The fact that Earth pulls on the moon and the moon pulls on Earth indicates that these two pulls make up an action-reaction pair, as stated in Newton's Third Law of Motion. B, C, and D are incorrect as the size of the objects does not determine the strength of their gravitational pull, but rather their mass and distance from each other.

Question 13

A player hits a ball with a bat.The action force is the impact of the bat against the ball.The reaction to this force is the
A)air resistance on the ball.
B)weight of the ball.
C)force that the ball exerts on the bat.
D)grip of the player's hand against the ball.
E)weight of the bat.

Accepted Answer

According to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. Therefore, the force that the ball exerts on the bat is the reaction to the action force of the impact of the bat against the ball.

Question 14

A piece of rope is pulled by two people in a tug-of-war.Each pulls with 400 N of force.What is the tension in the rope?
A)zero
B)400 N
C)600 N
D)800 N
E)none of these

Accepted Answer

The tension in the rope is equal to the force exerted by each person, which is 400 N. In a tug-of-war, the tension is the same throughout the rope and is equal to the force applied by each side.

Question 15

A player catches a ball.Consider the action force to be the impact of the ball against the player's glove.The reaction to this force is the
A)player's grip on the glove.
B)force the glove exerts on the ball.
C)friction of the ground against the player's shoes.
D)muscular effort in the player's arms.
E)none of these

Accepted Answer

According to Newton's third law, every action has an equal and opposite reaction. In this case, the action force is the impact of the ball against the player's glove, and the reaction force is the force the glove exerts on the ball to catch it. The other options are not related to this specific action-reaction pair.

Question 16

Two people,one twice as massive as the other,attempt a tug-of-war with 12 meters of massless rope on frictionless ice.After a brief time,they meet.The heavier person slides a distance of
A)3 m.
B)4 m.
C)6 m.
D)0 m.

Accepted Answer

Since there is no friction, the heavier person will continue to slide until the tension in the rope completely disappears. Let the acceleration of the heavier person be a and the acceleration of the lighter person be 2a (since the heavier person has twice the mass).

Using Newton's second law, F = ma, we can set up equations for the forces on each person: 
For the heavier person: 
T - mg = ma 
For the lighter person: 
mg - T = 2ma

To find when the tension in the rope goes to zero, we can set these two equations equal to each other: 
ma + mg = 2ma 
mg = ma 
a = g

So the acceleration of the heavier person is equal to the acceleration due to gravity. We can then use the equation vf^2 = vi^2 + 2ad to find how far the heavier person slides: 
0 = v^2 + 2ad 
d = v^2/2a

Since the heavier person starts with zero velocity, we just need to find the final velocity. Using the equation v = at, we get: 
v = at = (g)(t)

Now we just need to find the time it takes for the rope to become taut. This is the time it takes for the lighter person to move the entire length of the rope, which is 12m. Using the equation x = 1/2at^2, we get: 
12 = 1/2(2a)t^2 
t = sqrt(6/g)

Plugging in this value for t, we can find the distance the heavier person slides: 
d = v^2/2a = (g)(6/g)/2(g) = 3m

Therefore, the correct answer is choice B.

Question 17

A bird sitting on the limb of a tree is moving about 30 km/s with respect to the sun.If the bird takes 1 second to drop down to a worm below,the worm would be 30 km downrange from the bird when it reached the ground.This faulty reasoning is best countered with Newton's
A)first law.
B)second law.
C)third law.
D)law of gravitation.
E)none of these

Accepted Answer

Newton's first law, the law of inertia, states that an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. The bird and the worm are both moving with the Earth at 30 km/s, so the bird will land directly below where it started relative to the worm.

Question 18

Your friend says that the heavyweight champion of the world cannot exert a force of 50 N on a piece of tissue paper with his best punch.The tissue paper is held in midair - no wall,no tricks.You
A)agree that it can't be done.
B)have reservations about this assertion.
C)disagree,for a good punch easily delivers this much force.

Accepted Answer

A piece of tissue paper in midair cannot provide enough resistance to allow a force of 50 N to be exerted on it, as it would simply move away with the punch.

Question 19

The attraction of a person's body toward Earth is called weight.The reaction to this force is
A)the person's body pushing against Earth's surface.
B)the Earth's surface pushing against the person's body.
C)the person's body pulling on the Earth.
D)none of these

Accepted Answer

According to Newton's third law of motion, every action has an equal and opposite reaction. The force of gravity pulling the person's body toward Earth (weight) is matched by the person's body pulling on the Earth with an equal and opposite force.

Question 20

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the
A)engine.
B)tires.
C)air.
D)road.
E)none of these

Accepted Answer

The force that accelerates the car is exerted by the road on the tires due to friction. The engine provides power, but the road provides the reaction force that moves the car forward.

Quiz 5: Newtons Third Law of Motion: Action and Reaction

For an action force,there must be a reaction force that

As a ball falls,the action force is the pull of Earth on the ball.The reaction force is the

A baseball player bats a ball with a force of 1000 N.The reaction force that the ball exerts against the bat is

A karate chop delivers a blow of 3000 N to a board that breaks.The force that acts on the hand during this event is

A Mack truck and a Volkswagen traveling at the same speed have a head-on collision.The vehicle that undergoes the greatest change in velocity will be the

A automobile and a baby carriage traveling at the same speed collide head-on.The impact force is

A car traveling at 100 km/hr strikes an unfortunate bug and splatters it.The force of impact is

A person is attracted toward the center of Earth by a 500-N gravitational force.The Earth is attracted toward the person with a force of

An archer shoots an arrow.Consider the action force to be the bowstring against the arrow.The reaction to this force is the

Use the following figure to answer the question: -Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war.The greater force on the rope is exerted by

A skydiver falls towards the Earth.The attraction of the Earth on the diver pulls the diver down.What is the reaction to this force?

Earth pulls on the moon.Similarly the moon pulls on Earth,evidence that

A player hits a ball with a bat.The action force is the impact of the bat against the ball.The reaction to this force is the

A piece of rope is pulled by two people in a tug-of-war.Each pulls with 400 N of force.What is the tension in the rope?

A player catches a ball.Consider the action force to be the impact of the ball against the player's glove.The reaction to this force is the

Two people,one twice as massive as the other,attempt a tug-of-war with 12 meters of massless rope on frictionless ice.After a brief time,they meet.The heavier person slides a distance of

A bird sitting on the limb of a tree is moving about 30 km/s with respect to the sun.If the bird takes 1 second to drop down to a worm below,the worm would be 30 km downrange from the bird when it reached the ground.This faulty reasoning is best countered with Newton's

Your friend says that the heavyweight champion of the world cannot exert a force of 50 N on a piece of tissue paper with his best punch.The tissue paper is held in midair - no wall,no tricks.You

The attraction of a person's body toward Earth is called weight.The reaction to this force is

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the