1. At the top of a looped section of roller coaster track, the car and rider are completely upside down. Engineers calculated that the car may travel a minimum speed of 14.3 m/s to keep riders from falling out of the car at the top of the loop. What is the radius of the loop?
22.5 m
18.9 m
17.4 m
20.9 m
2. Future space stations could create an artificial gravity by rotating. Consider a cylindrical space station of 640-m diameter as it rotates about its axis. Astronauts walk on the inside surface of the space station. What rotation period will provide an Earth-like gravity, in which acceleration equals 9.8 m/s2?
8.1 s
5.7 s
51 s
36 s
3. A curved section of a roadway is in the shape of a circular arc of 240-m radius. The roadway is banked at an angle of 73A?°. What is the maximum speed that a vehicle may travel on the roadway without experiencing a net lateral acceleration?
88 m/s
70 m/s
62 m/s
68 m/s
4. At the top of a looped section of roller coaster track, the car and rider are completely upside down. The radius of the loop is At what minimum speed must the car traverse the loop so that the rider does not fall out of the car? Assume the rider is not strapped to the car.
12.8 m/s
14.9 m/s
10.1 m/s
14.1 m/s
5. An astronaut orbits planet X in his spaceship. To remain in orbit at above the planet's center, he maintains a speed of What is the mass of planet X? Note: the constant of universal gravity (G) equals 6.674 Af- 10 -11 N m2/kg2.
5.8 Af- 1019 kg
5.8 Af- 1016 kg
7.7 Af- 1017 kg
7.7 Af- 1014 kg
6. Two particles, A and B, are in uniform circular motion about a common center. The acceleration of particle A is 6.0 times that of particle B. Particle B takes 2.4 times as long for a rotation as particle A. What is the ratio of the radius of the motion of particle A to that of particle B?
14:1
1:1
5:1
1:3
7. A tetherball is tied to the end of a string of negligible mass. The ball is struck so that it moves in uniform circular motion in a horizontal plane, and the string makes an angle of 26A?° with the vertical pole. The mass of the ball is 1.3 kg. What is the ball's speed?
1.9 m/s
2.4 m/s
1.7 m/s
2.1 m/s
8. A satellite of mass M takes time T to complete one orbit around a planet. If the satellite had twice as much mass, what would be its period of rotation?
T/2
2T
4T
T
T/4
9. A ball is tied to the end of a length of string. A student holds one end of the string and whirls it so the ball travels in a vertical circle. The string is always taut. The tension in the string is highest when the ball is _____.
descending from the top to the bottom of the circle
at the bottom of the circle
ascending from the bottom to the top of the circle
at the top of the circle