# 5 multiple choice

1. Mar 6, 2008

### gavrir

1. The problem statement, all variables and given/known data
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.

I think the answers for 3,4, and 5 are C,A,and B but dont know the first two.

2. Mar 7, 2008

### Kurdt

Staff Emeritus
The following page should help you:

http://hyperphysics.phy-astr.gsu.edu/HBASE/circ.html

That means that your answer for 3 is wrong as are 4 and 5. Not sure about 4 since you haven't said what the mass is attached to but I assume its being held by a string attached to a mass hanging from the centre of the circle

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