# Homework Help: Easy 5 multiple choice

1. Mar 6, 2008

### gavrir

Hey guys i was taking some practice excercises and was wondering if someone could give me the answers to the following:

1.The following questions are about this experiment in which a test-mass moves in a horizontal circle at constant speed. What is the direction of the test-mass acceleration?

a. Downward
b. In the direction of velocity.
c. Towards the center of the circle.
d. Away from the center of the circle.
e. Upward.
f. Opposite the direction of the velocity.

2.What measurements will be made to determine the magnitude of the test-mass centripetal acceleration?
A. The test-mass mass
B. The test-mass velocity
C. The radius of the orbit
D. The weight of the hanging mass
E. The spring constant
F. The period of the orbital motion

1. B, C
2. A, D
3. C, F
4. B, E
5. A, B, D

3.A particle in uniform circular motion requires a net force acting in what direction?

a. Downward
b. Opposite the direction of the velocity.
c. Away from the center of the circle.
d. In the direction of velocity.
e. Towards the center of the circle.
f. Upward.

4. What supplies the force that keeps the test mass moving in uniform circular motion?

a. The string attached to the mass.
b. The spring that pulls on the string attached to the mass.
c. The weight of the hanging mass.
d. The string from the test-mass riser holding up the mass.
e. You -- as you keep the apparatus spinning.

5.How will the centripetal force be experimentally determined?

a. From the acceleration and mass of the test mass
b. From the weight of the hanging mass.
c. From the velocity, radius, and mass of the test mass.
d. The centripetal force is not determined in this experiment.

2. Mar 6, 2008

### pmb_phy

This question belongs in the Homework & Coursework Questions section at https://www.physicsforums.com/forumdisplay.php?f=152

I also believe that it is against forum policy not to give answer's to questions for which the person asking the question has not taken any effort to answer the question themselves. Therefore I recommend that you take some educated guesses to the questions above or if you are unable to then perhaps tell us where you are stumped and we can help you from there. Good luck!

Best wishes

Pete

3. Mar 6, 2008

### gavrir

I know the answers for 3,4,5 are c,a and b b ut i dont understand the first 2..Thanks