1. A machine that produces 102 J of work by using 120 J of energy has an efficiency of   15 %   18 J   85 %   17 J   Hint Half-n-half Clue   2. _______ is the capacity to do work.   Pressure   Energy   Force   Half-n-half Clue   3. The energy losses from machines are mostly dissipated as sound energy.   True   False   4. 'Energy can neither be created nor destroyed' is a statement of the   Law of Conservation of Energy   Law of Conservation of Matter   Law of Conservation of Electric Charges   Half-n-half Clue   5. Both work and heat are measured in Joules.   True   False   6. The energy acquired by a body because of its motion is called potential energy.   True   False   7. 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   28 m/s   14 m/s   4 m/s   Half-n-half Clue