1. The energy acquired by a body because of its motion is called potential energy.   True   False   2. The energy losses from machines are mostly dissipated as sound energy.   True   False   3. 'Energy can neither be created nor destroyed' is a statement of the   Law of Conservation of Energy   Law of Conservation of Electric Charges   Law of Conservation of Matter   Hint Half-n-half Clue   4. A boy throws a ball vertically upwards from ground level. If the ball reaches a maximum height of 160 m and the gravitational acceleration is 9.8 m/s2, with what speed did the boy throw the ball?   28 m/s   56 m/s   40 m/s   8 m/s   Half-n-half Clue   5. If there is no friction, the efficiency of a machine can be greater than 100 %.   True   False   6. A body loses 1960 J of potential energy in falling through 50 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   490 kg   4 kg   200 kg   39 kg   Half-n-half Clue   7. Kinetic energy of a body in motion equals the product of half its mass and the square of its _______   acceleration   distance   velocity   Half-n-half Clue