Question 1

A book rests on a table. Which of the following best describes the forces acting on the book?

Accepted Answer

There is a downward gravitational force and an upward normal force from the table.

Question 2

A box is being pulled to the right by a rope and pushed to the left by a compressed spring. If the forces are equal in magnitude, what is the net force on the box?

Accepted Answer

The net force is zero.

Question 3

Which of the following is an example of a long-range force?

Accepted Answer

Gravitational force from the Earth

Question 4

A skier is being pulled up a hill by a rope. Which force is responsible for the skier's acceleration up the hill?

Accepted Answer

The tension force in the rope

Question 5

According to Newton’s Second Law, what is the acceleration $$a of a$$ $$5\ \mathrm{kg}$$ object when a net force of $$20\ \mathrm{N} is $$applied?

Accepted Answer

$$a = 4\ \mathrm{m/s^2$}$$

Question 6

A frog sits on an inclined branch and does not slide down. Which force prevents the frog from sliding?

Accepted Answer

Static friction

Question 7

A rocket expels exhaust gases downward. According to Newton’s Third Law, what is the reaction force?

Accepted Answer

The rocket is pushed upward by the exhaust gases.

Question 8

Which of the following statements about inertial reference frames is correct?

Accepted Answer

A reference frame where Newton’s First Law holds is called inertial.

Question 9

A sled is moving to the right on snow. Which direction does the kinetic friction force act?

Accepted Answer

To the left

Question 10

A box is pulled by two ropes at angles as shown in the images. How do you determine the net force?

Accepted Answer

Add the force vectors using vector addition.

Question 11

Which of the following best describes the normal force?

Accepted Answer

It acts perpendicular to the surface.

Question 12

A car is cruising at constant speed on a straight road. Which law explains why it continues moving without slowing down (ignoring friction and air resistance)?

Accepted Answer

Newton’s First Law

Question 13

Which of the following is NOT a contact force?

Accepted Answer

Gravity

Question 14

A block is at rest on a horizontal surface. Which statement is true if the block remains at rest?

Accepted Answer

The net force on the block is zero.

Question 15

A ball is dropped from a height. Which force acts on the ball as it falls (ignoring air resistance)?

Accepted Answer

Gravitational force

Question 16

A compressed spring pushes a box to the right. What is the direction of the force exerted by the spring on the box?

Accepted Answer

To the right

Question 17

Which of the following best describes the unit of force, the newton ($$N$$)?

Accepted Answer

$$1\ N = 1\ kg \cdot m/s^2$

Question 18

A block is pulled across a rough surface at constant velocity. Which statement is true about the forces acting on the block?

Accepted Answer

The pulling force and friction force are equal in magnitude and opposite in direction.

Question 19

Which of the following is a correct statement of Newton’s Third Law?

Accepted Answer

For every action, there is an equal and opposite reaction.

Question 20

A car suddenly stops and you lurch forward. Which concept explains this phenomenon?

Accepted Answer

Inertia

Forces and Newton's Laws: Foundations of Dynamics

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