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

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.

Answer 1

is exactly equal in magnitude.

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

Answer 2

pull of the ball's mass on the Earth.

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.

Answer 3

1000 N.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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

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

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.

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

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.

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

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

Question 21

A vehicle that weights 400 N on the surface of the Earth is traveling in outer space at a speed of 400 m/s .It can be stopped by applying a constant force of 20 N for

A)2 seconds.
B)4 seconds.
C)80 seconds.
D)400 seconds.
E)800 seconds.

Question 22

A vehicle that weighs 4000 N on the surface of the Earth is travelling in outer space at a speed of 200 m/s.The smallest constant force that must be applied to stop it in 20 seconds is

A)20 N.
B)40 N.
C)400 N.
D)4000 N.
E)more than 4000 N.