Question 1

In uniform circular motion, which statement best describes the direction of the acceleration vector at any point on the circle?

Accepted Answer

It points inward, toward the center of the circle.

Question 2

A car makes a sharp right turn. From the perspective of an observer inside the car (non-inertial frame), which force is felt and in which direction?

Accepted Answer

Centrifugal force, toward the right.

Question 3

Which equation correctly represents the centripetal acceleration for an object in uniform circular motion?

Accepted Answer

$$a_c = \frac{v_T^2$}{r}$$

Question 4

What is the primary difference between an inertial and a non-inertial frame of reference?

Accepted Answer

Non-inertial frames are accelerating, while inertial frames are not.

Question 5

A digital scale measures your weight while you are in an elevator accelerating upward. What does the scale actually measure?

Accepted Answer

The normal force exerted by the floor.

Question 6

During uniform circular motion, what happens to the velocity vector?

Accepted Answer

Its direction changes but its magnitude remains constant.

Question 7

Which equation gives the centripetal force required to keep an object moving in a circle of radius $$r$$ with tangential velocity $$v_T$$?

Accepted Answer

$$F_c = m \frac{v_T^2$}{r}$$

Question 8

If you are in a plane accelerating downward at $$9.8\ 	ext{m/s}^2$$, what is your apparent weight?

Accepted Answer

Zero, because the normal force is zero.

Question 9

Which of the following best describes 'weightlessness' as experienced by astronauts in orbit?

Accepted Answer

A lack of normal force.

Question 10

A pendulum at its equilibrium point experiences which forces?

Accepted Answer

Both restoring force and centripetal force, perpendicular to each other.

Question 11

In a non-inertial frame of reference, which force is considered 'fictitious' and why?

Accepted Answer

Centrifugal force, because it arises from inertia and is not a real force.

Question 12

If a car travels in a circle with a constant speed, what is the net force acting on it?

Accepted Answer

A force directed toward the center of the circle.

Question 13

When an elevator accelerates downward, how does your apparent weight change?

Accepted Answer

It decreases.

Question 14

Which force is responsible for changing the direction of velocity in uniform circular motion?

Accepted Answer

Centripetal force.

Question 15

A NASCAR car takes a banked turn. Which force(s) contribute to the centripetal force?

Accepted Answer

Both normal force and friction.

Question 16

If the radius of a circle is doubled while keeping the tangential velocity constant, what happens to the centripetal acceleration?

Accepted Answer

It halves.

Question 17

Which of the following is NOT a condition for experiencing weightlessness?

Accepted Answer

Being outside the influence of gravity.

Question 18

In uniform circular motion, how is the change in velocity ($$\Delta \vec{v}) $$calculated?

Accepted Answer

$$\Delta \vec{v} = \vec{v}_f - \vec{v}_i$$

Question 19

Which statement about pendulums and uniform circular motion is correct?

Accepted Answer

Pendulums do not have constant tangential speed, so they are not uniform circular motion.

Question 20

When the frame of reference is accelerating in the same direction as the object, how do you calculate the net acceleration?

Accepted Answer

Add the accelerations.

Uniform Circular Motion, Frames of Reference, and Apparent Weight

Study Guide - Practice Questions