Question

I've had several mental breakdowns please help me

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 constant speed. Find the efficiency of the system consisting of the motor and the lift .


The answer is 31% but please explain how to do this


I'LL GIVE BRAINLIEST!!!!! NO LINKS ISTG

Answer 1

Answer:

The efficiency of the system is 63.7 %

Explanation:

Given;

input power of the motor, = 1.5 kW = 1,500 W

mass of the car lifted, m = 1300 kg

height through which the car was lifted, h = 1.8 m

time, t = 24 s

The output power of the motor is calculated as;

Output Power = F x v

                        = (mg)  x (d/t)

                        = (1300 x 9.8) x (1.8 / 24)

                        = 12,740 x 0.075

                        = 955.5 W

The efficiency of the system is calculated as;

$E = \frac{0utput \ power}{1nput \ power} \times \ 100\%\\\\E = \frac{955.5}{1500} \times \ 100\% \\\\E = 63.7 \ \%$

The correct answer is 63.7%