1. A body loses 8820 J of potential energy in falling through 90 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   900 kg   882 kg   98 kg   10 kg   Hint Half-n-half Clue   2. A body loses 8085 J of potential energy in falling through 75 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   735 kg   11 kg   825 kg   108 kg   Half-n-half Clue   3. A boy throws a ball vertically upwards from ground level. If the ball reaches a maximum height of 40 m and the gravitational acceleration is 9.8 m/s2, with what speed did the boy throw the ball?   28 m/s   4 m/s   14 m/s   20 m/s   Half-n-half Clue   4. Both work and heat are measured in Joules.   True   False   5. If an engine does 470 J of work in 5 seconds, its average power is   465 W   2350 W   475 W   94 W   Half-n-half Clue   6. By definition, work is done when a _______ moves through a distance.   force   mass   pressure   Half-n-half Clue   7. The energy possessed by a body due to its position or configuration is called _______ energy.   thermal   kinetic   sound   potential   Half-n-half Clue