Question

A piano with a mass of 130 kg is lifted 10m above the ground in 5 s by a crane. What is the power used by the crane, measured in watt?

Answer 1

To calculate the power used by the crane, we can use the formula: Power = Work/Time, where the work done by the crane is equal to the force applied multiplied by the distance moved.

Step-by-step explanation:

To calculate the power used by the crane, we can use the formula: Power = Work/Time. Since the work done by the crane is equal to the force applied multiplied by the distance moved, we can rewrite the formula as: Power = Force * Distance/Time. The force applied by the crane is equal to the weight of the piano, which can be calculated using the formula: Force = Mass * Acceleration due to gravity. Substituting the values, we can calculate the force and then multiply it by the distance lifted and divide it by the time taken to find the power used by the crane.

Answer 2

The power used by the crane = 2548 W

Step-by-step explanation:

Power: Power can be defined as the rate at which energy is dissipated or expended. The S.I of power is Watt (W). It can be express mathematically as,

Power (P) = Energy/time......................................... Equation 1

But, Energy = mgh..................................................... Equation 2

Where m = mass of the body, g = acceleration due to gravity, h = height.

Given:m = 130 kg, h = 10 m

Constant: g = 9.8 m/s²

Substituting these values into equation 2

Energy = 130×10×9.8

Energy = 12740 J.

Also Given: t = 5 s

Substituting these values into equation 1

Power = 12740/5

Power = 2548 W

Therefore the power used by the crane = 2548 W