Problem Set Four
1. . A car weighing 14,000 N is speeding down the highway at 80 km/h. What is its momentum?
2. Two ice skaters stand face to face and “push off” and travel directly away from each other. The boy has a velocity of 5 m/s and he weighs 750 N. The girl weighs 480 N. What is the girl’s velocity?
3. A 20,000 kg railroad car is traveling at 5 m/s when it collides and couples with a second, identical car at rest. What is the resulting speed of the combined cars?
4. A soccer player kicks a 2 kg ball with a force of 900 N. His toe is in contact with the ball for 2 s. What is the impulse?
5. A force of 140 N is required to push a table 5.0 meters across a level floor. How much work was done?
6. If 10,000 J of work was done to raise a 225 kg box, how high was the box raised?
7. What is the velocity of a 1,500 kg car if its kinetic energy is 350 kJ?
8. A 125 kg mass is on a cliff 55 m high. What is its potential energy?
9 How much work is done moving a 2.4 kg book to a shelf 4.0 m high?
10. A 150 pound man runs up a stairway 20 feet above ground level in 15 s. How much work did the man do?