1. The energy losses from machines are mostly dissipated as sound energy.   True   False   2. When a current is supplied by a battery, _______ energy is converted to electrical energy.   chemical   mechanical   nuclear   Hint Half-n-half Clue   3. A body loses 4165 J of potential energy in falling through 85 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   833 kg   49 kg   425 kg   5 kg   Half-n-half Clue   4. The SI unit of power is   Watt   Joule   Volt   Half-n-half Clue   5. By definition, work is done when a _______ moves through a distance.   force   mass   pressure   Half-n-half Clue   6. Efficiency of a machine equals   Work Input / Work Output × 100 %   Work Input / (Work Input + Work Output) × 100 %   Work Output / Work Input × 100 %   Work Output / (Work Input + Work Output) × 100 %   Half-n-half Clue   7. The maximum amount of work that can be done by a 40 kW machine in 12 seconds is   3 J   480 J   3 kJ   480 kJ   Half-n-half Clue