A motor that uses electrical energy at a rate of 1.5 kW is connected to a hydraulic lift that is used to lift a 1300 kg car to a height of 1.8 m in 24 s at a constant speed. Find the efficiency of the system consisting of the motor and the lift.

Question

anonymous · Answer

let's calculate the work done by lift
work_H=force*distance

work_H=force* distance= mass* gravity*distance

power_H= work/time=  mass*gravity*distance /time

once you find that  power_H(power of hyrdaulic), divide it by power by motor

     Power(by Hydraulic)
    ----------------   = efficiency 
       power(motor)