Name _______________________________________________________
Date _____________
Per ______
Circular Motion and Gravity Review
1. A tennis ball is rotated on a string so that it completes four (4) rotations in one (1) second. The period (T) of
rotation is
2. Tangential (or linear) velocity refers to
3. Angular (or rotational) velocity refers to
4. Frequency ( f ) is related to the period ( T ).
5. The units of frequency are
6. A car engine is spinning at 40 revolutions per second. Its angular velocity () is
7. A washer is swung on a string in a horizontal circle. What is providing the centripetal force keeping the washer in
circular motion?
Two cars are going around two different tracks. Track A has a radius that is twice as large as track B. Use the following
diagram for the next three (3) questions:
8. If the both cars complete one lap in exactly the same amount of time, which car has a greater angular velocity?
9. If the both cars complete one lap in exactly the same amount of time, which car has a greater tangential velocity?
10. If both cars are going at exactly the same tangential velocity, which car requires the greater centripetal force to stay
on the track? (both cars have identical masses)
11. If object O is moving in a uniform circular motion around point P at constant speed, which vector shown represents
a centripetal force?
a.
b.
c.
d.
12. An object traveling with uniform circular motion has a centripetal acceleration due to the change in
13. An object on the end of a string rotates clockwise as shown in the diagram. If the string breaks when the object is
at point X, which arrow below best represents the path of the object after the string has broken?
a.
b.
c.
d.
14. A satellite orbiting the earth is experiencing
15. What is the gravitational force between two trucks, each with a mass of 2.0  104 kg, that are 2.0 m apart?
(G = 6.673  10–11 Nm2/kg2)
16. A meteor is 6e10 km distance from the earth and experiences a gravitational force from the earth of F Newtons.
When the meteor is 1e10 km from the earth (6 times closer) the force would be
17. The weakest force in nature is the
18. Suppose that two objects attract each other with a gravitational force of 16 Newtons. If the distance between the
two objects is doubled, what is the new force of attraction between the two objects?
19. Gravitational force is based on what physical property of an object?
20. In order to reduce the required centripetal acceleration for a car driving around a turn, the driver could
21. If a yo-yo is spinning so that it makes 180 revolutions every minute, what is its period?
22. A roller coaster loaded with passengers has a mass of 3.0  103 kg; the radius of curvature of the track at the lowest
point of the track is 20 m. If the vehicle has a tangential speed of 15 m/s at this point, what force is exerted on the
vehicle by the track?
23. What is the gravitational force between two trucks, each with a mass of 3.0  104 kg, that are 2.5 m apart?
(G = 6.673  10–11 Nm2/kg2)
24. Suppose you are at the center of a large freely rotating horizontal turntable in a carnival fun house. As you crawl
toward the edge, the angular speed of you and the turntable
25. A student is swinging a 0.0235 kg washer on a 0.8 meter string in a circle. When he lets go of the string, the washer
has a linear velocity of 20 m/s as it hits the student’s teacher in the head.
a) What was the centripetal acceleration for the washer just before the student let go of the string?
b) What was the tension on the string before the student let go of it?
c) If the washer makes an indentation of 0.05 meters into the teacher’s forehead, what is the force that it hit the
teacher?
26. Asteroid YU55 passed within 325, 453, 110 meters of the earth and has a mass of 65, 725 kg. The earth has a mass
of 5.97x1024 kg.
a) What is the force of attraction between the earth and YU55 as it approached at its closest point?
b) The mass of the moon is 7.349x1022 kg and has an average distance from the earth of 384,403,000 m. What is
the force of attraction between the moon and the earth?
27. The wheel attached to a bicycle has a diameter of 65 cm.
a) In one complete rotation of the wheel, how far does the bicycle travel? (give answer in m)
b) If the wheel rotates 6 rotations in a second, what is its period what is its frequency?
c) If the wheel makes 6 rotations in a second, how fast is the cyclist travelling (give answer in m/s)?