1. A child has legs that are each 0.500 m long. What is her maximum walking speed?
2.19 m/s
2.21 m/s
2.6 m/s
5.58 m/s
2. 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
3. Planet Z has diameter 1.8 x 107 m. On the planet's surface, the acceleration due to gravity is 19.5 m/s2. What is the mass of the planet? Note: The constant of universal gravity (G) equals 6.674 x 10-11 N · m2/kg2.
2.4 x 1025 kg
7.0 x 1025 kg
8.4 x 1025 kg
4.3 x 1025 kg
4. As shown in the diagram, two massless wires connect a rotating pole to a sphere.The sphere has mass 7.2 kg and it revolves in a horizontal circle at constant speed. At this particular speed the tension is the same in both wires. What is the speed of the ball?
2.9 m/s
4.0 m/s
5.7 m/s
4.6 m/s
5. Two people, each of mass 85 kg, are positioned 8.0 m away from each other. What is the magnitude of the gravitational attraction between them? Note: The constant of universal gravity (G) equals 6.674 x 10-11 N · m2/kg2.
1.1 x 103 N
7.5 x 10-9 N
8.9 x 10-11 N
6.0 x 10-8 N
7.1 x 10-10 N
6. A racecar experiences a centripetal acceleration of 36.0 m/s2 as it travels at a constant speed of 27.0 m/s along a circular arc. What is the radius of the circle?
0.18 m
20 m
9.3 m
14 m
7. A particle travels in a circle of radius 76 cm and completes one revolution in 4.5 s. What is the centripetal acceleration of the particle?1.5 m/s2
0.97 m/s2
3.3 m/s2
2.8 m/s2
8. A merry-go-round of diameter revolves at a rate of What is the velocity of a child who is seated at the outer edge of the merry-go-round?
1.2 m/s
5.5 m/s
15.6 m/s
7.8 m/s
9. Which scientist did not directly contribute to the equations that make up the laws of planetary motion?
Isaac Newton
Tycho Brahe
Johannes Kepler
Galileo Galilei
10. Satellite B revolves around Earth 4 times a day. What is the radius of its orbit, measured from Earth's center? Assume that Earth generates the only significant gravitation attraction on the satellite. Note: The mass of Earth is 5.98 x 1024 kg, and the constant of universal gravity (G) equals 6.674 x 10-11 N · m2/kg2.
1.68 x 107 m
6.03 x 106 m
2.11 x 107 m
6.70 x 107 m
11. An astronaut has weight W on Earth. The astronaut travels to a planet that has a mass 4 times greater than Earth's mass, and its radius is 2 times greater than Earth's radius. What is the astronaut's weight on the planet?
4W
0.5W
W
2W
12. The gravitational acceleration at the surface of planet X is 11.6 m/s2, and the radius of the planet is 66,500 km. An astronaut is hovering at height h above the planet's surface, and she notices her weight is the same as it is on Earth. What is h?
8200 km
7000 km
5800 km
9400 km
13. Earth's radius is 6380 km. An object is dropped from a height 622 km above Earth's surface. What is its initial acceleration in terms of g, the acceleration constant due to gravity at Earth's surface?
0.375g
0.831g
1.33g
0.426g
14. At the top of a looped section of roller coaster track, the car and rider are completely upside down. What information is necessary to calculate the minimum speed of the car that will prevent a rider from falling out of it? Assume the rider is not strapped into the car.
the radius of the loop, the mass of the rider. and the mass of the car
the radius of the loop
the mass of the rider and the width of the track
the radius of the loop and the mass of the rider
15. A merry-go-round revolves at a rate of A child who is seated at the outer edge of the merry-go-round travels at 6.9 m/s. What is the diameter of the merry-go-round?
7.5 m
16 m
9.9 m
19 m
16. A proton is oribiting a black hole at a speed of 0.999 times the speed of light, which is 3.0 x 108 m/s The radius of the orbit is from the center of the attractor. What is the mass of the black hole? Note: the constant of universal gravity (G) 6.674 x 10-11 N · m2/kg2.
2.34 x 1036 kg
2.34 x 1025 kg
2.34 x 1030 kg
2.34 x 1033 kg
17. 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
18. 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
19. 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 73°. 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
20. 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
21. 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 x 10-11 N · m2/kg2.
5.8 x 1019 kg
5.8 x 1016 kg
7.7 x 1017 kg
7.7 x 1014 kg
22. 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
23. 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 26° 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.