Apump is driven by electric motor with an efficiency of 0.87and with theoretical output of 22.2 gpm actually produces only 19.1 gpm. the pressure at the pump outlet is 2850 psi. if the pump has a mechanical efficiency of 0.97, what input horsepower is required to drive the pump? the electric motor is being operated for 15 hours a day and 235 day a year, how much electricity cost at $0.77 per kilowatt hour. how much operating cost is wasted yearly?

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c