Question 1

A soccer player kicks a ball with a force of 1500 N. According to Newton's third law, what is the magnitude of the force that the ball exerts back on the player's foot?

Accepted Answer

1500 N

Question 2

When you step off a curb, Earth pulls you downward with a force equal to your weight. What is the reaction force according to Newton's third law?

Accepted Answer

You pulling Earth upward

Question 3

A high-speed bus collides head-on with a flying bug. Which force is greater during the collision: the force on the bug or the force on the bus?

Accepted Answer

Both forces have the same magnitude

Question 4

When a cannon is fired, the cannonball and the cannon experience different accelerations. Why?

Accepted Answer

Their masses are different

Question 5

Two people of equal mass are on slippery ice and push off from each other. What happens?

Accepted Answer

Both move at the same speed in opposite directions

Question 6

A bird is able to fly by:

Accepted Answer

Pushing air downward so that the air pushes it upward

Question 7

Slightly tilted wings of airplanes deflect oncoming air in which direction to produce lift?

Accepted Answer

Downward

Question 8

Compared with a lightweight glider, a heavier glider must push air:

Accepted Answer

Downward with greater force

Question 9

Which of the following best describes Newton's third law of motion?

Accepted Answer

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first

Question 10

A car's tires push backward against the road. According to Newton's third law, what is the reaction force?

Accepted Answer

The road pushes the tires forward

Question 11

A jet engine pushes exhaust gases backward. What is the reaction force that moves the jet forward?

Accepted Answer

The exhaust gases push the jet forward

Question 12

If the mass of an object is doubled while the net force acting on it remains the same, what happens to its acceleration according to Newton's second law?

Accepted Answer

It is halved

Question 13

Which of the following is always true for action and reaction forces?

Accepted Answer

They are equal in magnitude and opposite in direction

Question 14

A helicopter hovers in midair. If the lift produced by the blades is exactly equal to the helicopter's weight, what is the motion of the helicopter?

Accepted Answer

It hovers in place

Question 15

Nellie Newton pulls a sled with a force $$F at an $$angle. Which component of her force is greater if the angle is less than 45 degrees?

Accepted Answer

The horizontal component $$F_x$$

Question 16

As a ramp is raised, which force acting on a block of ice remains constant?

Accepted Answer

The gravitational force $$mg$$

Question 17

As the angle of a ramp increases, what happens to the normal force $$N$$ acting on a block resting on the ramp?

Accepted Answer

It decreases

Question 18

When the ramp is vertical ($$90^\circ$$), what is the net force acting on the block of ice?

Accepted Answer

$$mg$$

Question 19

The apple-orange system will move with constant speed if:

Accepted Answer

Another external force counteracts the friction force on the apple’s feet

Question 20

Which component of the gravitational force $$mg is $$equal and opposite to the normal force $$N on an $$inclined plane?

Accepted Answer

The component of $$mg$$ perpendicular to the plane

Newton’s Third Law of Motion and Vectors: Study Notes

스터디 가이드 - 연습 문제

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