1. Power is the rate of doing work.   True   False   2. The SI unit of power is   Volt   Watt   Joule   Hint Half-n-half Clue   3. A carton is pulled along the ground for a distance of 8 m. If the average frictional force is 91 N, then the work done is   5824 J   91 J   728 J   8 J   Half-n-half Clue   4. A machine that produces 126 J of work by using 140 J of energy has an efficiency of   90 %   18 J   10 %   14 J   Half-n-half Clue   5. If an engine does 776 J of work in 8 seconds, its average power is   784 W   97 W   6208 W   768 W   Half-n-half Clue   6. By definition, work is done when a _______ moves through a distance.   force   pressure   mass   Half-n-half Clue   7. _______ is the capacity to do work.   Energy   Force   Pressure   Half-n-half Clue