You are assigned to select a new 5hp motor for an industrial facility. the motor will operate at essentially rated load for two shifts a day, five days a week. you have a couple of options, a nepact motor with an efficiency of 88.2% and a cost of $235 or a nema premium motor with an efficiency of 90.5% and a cost of $320. power costs a $0.10/kwh. how long is the payback period for the higher efficiency motor? what would be the cost savings over the 20-year lfe of the motor?