Circular Motion Test

Question 1

A 2.5 kg object moves at a constant speed of 8.0 m/s in a 5.0 m radius circle. What is the object’s acceleration?

A. 0 m/s^2
B. 1.6 m/s^2
C. 13 m/s^2
D. 32 m/s^2

Answer 1

C. 13 m/s^2

Question 2

An empty 12 kg seat, which is swung around in a horizontal circle, on a swing-type ride at the fairgrounds, has a velocity of 8.94 m/s. (radius of 7.0 m)

A. 1.2 x 10^2 N
B. 1.4 x 10^2 N
C. 8.2 x 10^2 N
D. 5.8 x 10^3 N

Answer 2

B. 1.4 x 10^2 N

Question 3

A 1.5 kg object is in uniform circular motion with a period of 3.0 s. If the radius of the path is 4.0 m, what is the centripetal force on the object?

A. 18 N
B. 26 N
C. 41 N
D. 59 N

Answer 3

B. 26 N

Question 4

A 75 kg person rides a Ferris wheel which is rotating uniformly. The centripetal for acting on the person is 45 N

What force does the seat exert on the rider at the top and at the bottom of the ride?

Force at Top          Force at bottom
 A. 690 N                 690 N
 A. 690 N                 780 N
 A. 780 N                 690 N
 A. 780 N                 780 N

Answer 4

Force at Top Force at bottom

A. 690 N 780 N

Question 5

A 65 kg pilot in a stunt plane performs a vertical loop with a 700 m radius. The plane reaches a speed of 210 m/s at the bottom of the loop. What is the upward force on the pilot at the bottom of the loop?

A. 640 N
B. 3500 N
C. 4100 N
D. 4700 N

Answer 5

D. 4700 N

Question 6

A test tube with amoeba rotates in a centrifuge with a period of 1.20 x 10^-3 s. The bottom of the test tube travels in a circular path of a radius of 0.150 m.

(radius= 0.150 m)

What is the centripetal force exerted on a 2.00 x 10^-8 kg amoeba at the bottom of the tube?

A. 9.86 x 10^-5 N
B. 2.08 x 10^-3 N
C. 8.22 x 10^-2 N
D. 4.11 x 10^6 N

Answer 6

C. 8.22 x 10^-2 N

Question 7

A physics student swings a 5.0 kg pail of water in vertical circle of radium 1.3 m.

What is the minimum speed, v, at the top of the circle if the water is not to spill from the pail?

A. 3.6 m/s
B. 6.1 m/s
C. 8.0 m/s
D. 9.8 m/s

Answer 7

A. 3.6 m/s

Question 8

An object is attached to a string that can withstand a maximum tension force of 6.3 N. The object travels in circular path of radius 0.40 m with a period of 2.1 s.

What is the maximum mass of the object.

A. 0.57 kg
B. 0.64 kg
C. 1.8 kg
D. 3.6 kg

Answer 8

C. 1.8 kg