Question 1

Which of the following best describes the difference between mass and weight?

Accepted Answer

Mass is a scalar quantity measured in kilograms, while weight is a vector quantity measured in newtons.

Question 2

A 5 kg object is suspended by a rope and remains at rest. What is the tension in the rope? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$T = 49\ \mathrm{N}$$

Question 3

Which of the following is NOT a contact force?

Accepted Answer

Gravitational force

Question 4

A car of mass $$m$$ accelerates at $$a$$ due to a net force $$F. $$Which equation correctly relates these quantities according to Newton's Second Law?

Accepted Answer

$$F = m 	imes a$$

Question 5

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

Accepted Answer

The applied force is equal to the frictional force.

Question 6

Which of the following best describes Newton's First Law?

Accepted Answer

An object at rest remains at rest, and an object in motion remains in motion at constant velocity unless acted upon by a net external force.

Question 7

A ball is dropped from rest. Which free-body diagram correctly represents the forces acting on the ball as it falls (neglecting air resistance)?

Accepted Answer

A downward arrow labeled 'gravity' only.

Question 8

A person stands on a scale in an elevator accelerating upward at $$2\ \mathrm{m/s^2$}. If $$the person's mass is $$70\ \mathrm{kg}$$, what is the reading on the scale? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$826\ \mathrm{N}$$

Question 9

Which of the following is an example of a non-inertial reference frame?

Accepted Answer

A train accelerating as it leaves the station.

Question 10

A 2 kg object moves in a circle of radius 0.5 m at a constant speed of 4 m/s. What is the magnitude of the centripetal force acting on the object?

Accepted Answer

$$F_c = 32\ \mathrm{N}$$

Question 11

Which equation gives the angular speed $$\omega$$ for an object moving in a circle of radius $$r at $$speed $$v$$?

Accepted Answer

$$\omega = v/r$$

Question 12

A satellite orbits Earth in uniform circular motion. Which force provides the required centripetal acceleration?

Accepted Answer

Gravitational force

Question 13

A child swings a ball attached to a string in a horizontal circle. What is the direction of the tension force in the string?

Accepted Answer

Radially inward toward the center of the circle

Question 14

Which of the following statements about centripetal and centrifugal forces is correct?

Accepted Answer

Centripetal force is a real force directed toward the center; centrifugal force is a fictitious force observed in non-inertial frames.

Question 15

A car of mass $$m$$ rounds a curve of radius $$r at $$speed $$v. $$What is the minimum coefficient of friction $$\mu$$ required to prevent skidding?

Accepted Answer

$$\mu = v^2$/(g r)$$

Question 16

A block is at rest on a horizontal surface. Which statement is true about the forces acting on the block?

Accepted Answer

The normal force is equal in magnitude and opposite in direction to the gravitational force.

Question 17

A 1 kg object moves in a circle of radius 2 m at a constant angular speed of $$3\ \mathrm{rad/s}. $$What is the magnitude of the centripetal acceleration?

Accepted Answer

$$a_c = 18\ \mathrm{m/s^2$}$$

Question 18

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 acting on different objects.

Question 19

A person pushes a box across the floor. Which force diagram best represents the forces acting on the box?

Accepted Answer

Four arrows: gravity downward, normal force upward, applied force right, friction force left.

Physics Study Guide: Newton's Laws and Circular Motion

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