Question

A set of pulleys is used to lift a piano with a mass of 102 kg. The piano is lifted 3 meters in 1 minutes. How much power is used?

Answer 1

50.031 watts

Explanation:

Formula

Power = Force * distance / time

The units are critical

distance = meters

time = seconds

force = newtons = kg * m / s^2

Solution

F = m * a

a = 9.81

m = 102 kg

F = 102 * 9.81 = 1000.62 Newtons

T = minute = 60 sec/min * 1 min

T = 60 seconds

d = 3 meters

Power = 1000.62 * 3 / 60

Power = 50.031