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A fully loaded, slow-moving freight elevator has a cab with a total mass of 1250 kg, which is required to travel upward 53 m in 3.1 min, starting and ending at rest. The elevator's counterweight has a mass of only 975 kg, and so the elevator motor must help. What average power is required of the force the motor exerts on the cab via the cable?

1 Answer

7 votes

Answer:

P= 783.6 W

Step-by-step explanation:

Given that

Total mass M= 1250 Kg

d= 53 m ,in time t= 3.1 min

Counter weight mass ,m = 975 kg

The total net force F

F= M g - m g

F= (1250 - 975 ) x 10 N ( take g =10 m/s²)

F=2750 N

We know that work done by force F

W= F. d

W= 2750 x 53 J

W=145750 J

The power P is the rate of change of work with time .


P=(W)/(t)


P=(145750)/(3.1* 60)\ W

P= 783.6 W

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User Milan Gupta
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