1. A mass of 70 kg is moved vertically upwards through a distance of 9 m. If the gravitational acceleration is 9.8 m s-2, then the work done against gravity is   630 J   88.2 J   686 J   6174 J   Hint Half-n-half Clue   2. Kinetic energy of a body in motion equals the product of half its mass and the square of its _______   distance   acceleration   velocity   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?   20 m/s   14 m/s   4 m/s   28 m/s   Half-n-half Clue   4. When a current is supplied by a battery, _______ energy is converted to electrical energy.   nuclear   chemical   mechanical   Half-n-half Clue   5. The energy possessed by a body due to its position or configuration is called _______ energy.   potential   sound   thermal   kinetic   Half-n-half Clue   6. The maximum amount of work that can be done by a 20 kW machine in 8 seconds is   2 J   160 J   2 kJ   160 kJ   Half-n-half Clue   7. By definition, work is done when a _______ moves through a distance.   mass   force   pressure   Half-n-half Clue