Question 1

Which of the following best describes Newton's 1st Law of Motion?

Accepted Answer

An object will remain at rest or in uniform motion unless acted upon by a net external force.

Question 2

A car is pushed by a person. According to the definition of force, which is the agent and which is the object?

Accepted Answer

The person is the agent and the car is the object.

Question 3

Which equation correctly represents Newton's 2nd Law of Motion?

Accepted Answer

$$F_{net} = m \cdot a$$

Question 4

A skier is moving down a slope. Which forces are acting on the skier?

Accepted Answer

Normal force, kinetic friction, and drag force.

Question 5

Which of the following is a long-range force?

Accepted Answer

Gravitational force

Question 6

What is the direction of the normal force exerted by a table on a book?

Accepted Answer

Perpendicular to the surface of the table

Question 7

Which formula gives the period $$T of an $$object in uniform circular motion?

Accepted Answer

$$T = \frac{2\pi r}{v}$$

Question 8

A box is at rest on a rough surface. Which force prevents it from moving when a weak force is applied?

Accepted Answer

Static friction

Question 9

Why is kinetic friction always less than static friction at the sub-macroscopic scale?

Accepted Answer

Once rough edges slide past one another, they become smoother, decreasing the sticking force.

Question 10

Which of the following is NOT a contact force?

Accepted Answer

Gravitational force

Question 11

A spring is stretched by a hand. What is the direction of the spring force on the hand?

Accepted Answer

Opposite to the direction of displacement

Question 12

Which equation represents the restoring force of a spring according to Hooke's Law?

Accepted Answer

$$F_{spring} = -k \Delta y$$

Question 13

What is the direction of the tension force in a rope pulling a sled?

Accepted Answer

Along the rope, away from the sled

Question 14

Which force is responsible for slowing down a moving object in air?

Accepted Answer

Drag force

Question 15

Which of the following statements about frictional forces is correct?

Accepted Answer

Frictional forces can occur in solids, liquids, and gases.

Question 16

A rocket expels gas molecules at high speed. What is the direction of the thrust force?

Accepted Answer

Opposite to the direction in which the exhaust gas is expelled

Question 17

Which force always points toward the center of the Earth for a static observer outside of Earth?

Accepted Answer

Weight (gravitational force)

Question 18

Which of the following best describes Newton's 3rd Law of Motion?

Accepted Answer

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

Question 19

Which equation gives the angular position $$	heta in $$terms of angular velocity $$\omega$$ and time $$t$$?

Accepted Answer

$$	heta = \omega t$$

Question 20

Which force is always perpendicular to the surface and results from many molecular springs being compressed?

Accepted Answer

Normal force

Dynamics and Forces: Newton’s Laws and Types of Forces

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