posted by sean .
How many seconds would it take a 7.00hp motor to raise a 475 lb boiler to a platform 38.0 ft high?
Power = 7.0hp * 746W/hp = 5222 Watts =
Mass = 475Lbs * 0.454kg/Lb = 215.65 kg.=
Mass of boiler.
d = 38Ft./3.3Ft/m = 11.52 m.
Work=F*d = mg * d=215.65*9.8 *11.52=
t = 24346J * 1s/5222J = 4.66 s.