Suppose a moving car has 2000 j of kinetic energy. if the carʹs speed doubles, how much kinetic energy would it then have?
a) 8000 j
b) 6000 j
c) 1000 j
d) 4000 j
e) 2000 j

A75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. the motor operates 4368 hours a year at a load factor of 0.75. taking the cost of electricity to be $0.12/kwh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. also, determine the simple payback period if the pu