Pre AP Physics Circular Motion Review Sheet
Complete all problems.
1. When a car goes around a curve, what force keeps the car on the road?
2. What is the direction of the centripetal acceleration of an object in uniform circular motion? Why?
3. A ball is whirled around in a circle. What happens to the centripetal acceleration if the velocity is doubled?
4. If a string breaks that holds a whirling can in it circular path, what causes it to move in a straight line path?
5. What is the centripetal force that keeps a satellite in orbit above the earth?
6. According to Newton’s law of universal gravitation, the force of gravitational attraction between any two masses is directly related to the ______of the objects and inversely related to the ______of the distance between their centers.
7. A 2400 kg car rounds a curve of radius 90.8 m with a speed of 12.50 m/s. If its wheels are on the verge of slipping on the road, what is the force of friction? [4129.956 N]
8. Determine the speed of channel 19’s communications satellite orbiting at a height of 5.96 x 105 m above the earth’s surface. [7561.51 m/s]
9. A model airplane is guided in a horizontal circular path by a cord of length 11 m. If it has a constant speed of 28 m/s and a mass of 0.90 kg, what is the tension in the cord? [64.145 N]
10. What is the centripetal acceleration of an object moving in a horizontal circular path of 0.045 km radius with a speed of 40 m/s? [35.556 m/s2]
11. The radius of the moon’s path about the earth is about 3.84 x 108 m. The moon’s period is 27.3 days. What is the centripetal acceleration of the moon? [0.0027 m/s2]
12. A child whirls a stone of mass 6.7 kg in a vertical circle on the end of a string 0.8 m long. The velocity of the stone is 14 m/s. Calculate the tension in the string at the bottom of the circle. [1707.16 N]
b. What is the tension in the cord at the top of the circle? [1575.84 N]
13. An automobile travels around a circular track of radius 430 m at a speed of 22 m/s. What is the coefficient of friction needed to keep this car on the track? [0.115]
14. The planet Neptune has two known moons – Triton and Nereid. Triton, which is larger than our moon, orbits at a distance from Neptune’s center of 3.48 x 105 km in 5.9 days. What is Triton’s velocity? [4289.369 m/s]
15. What is the weight, in N, of a 6 kg mass at the surface of the planet Persephone if the acceleration due to gravity is 6.5 m/s2? [39 N]
16. A communications satellite of mass 600 kg is in circular orbit of radius 8.38 x 106 m above the Earth’s surface. What is the gravitational force on the satellite? [1098.51 N]
17. The Enterprise, of mass 7.00 x 106 kg is in a 543 m radius orbit around a spaceport for repairs and rest. If the spaceport has a mass of 2.8 x 109 kg, how fast is the ship moving in its orbit? [0.019 m/s]
18. Two balls have their center of mass 10.0 m apart. One weighs 39.2 N, the other weighs 39.2 N. what is the gravitational force between them? [1.067 x 10-11 N]
19. A 2 kg bucket of water is tied by a rope and whirled in a circle with a radius of 1.2 m. At the top of the circular loop, the speed of the bucket is 3.8 m/s. Determine the acceleration, the net force and the individual force values when the bucket is at the top of the circular loop. [12.033m/s2, T = 4.467 N, Fnet = 24.067 N, Fg = 19.6 N]
b. Determine the acceleration, the net force and the individual force values when the bucket is at the bottom of the circular loop, if it is traveling at 4.6 m/s. [17.633 m/s2, T = 54.867 N, Fnet = 35.267 N, Fg = 19.6 N]