A crane can lift a 900 kg mass to height of 50 m in 2 minutes. Calculate the work

done by the crane.

The work done by the crane is, W = 441000 J

The power of the crane is, p = 3675 watts

Explanation:

Given data,

The mass of the object, m = 900 kg

The object is lifted to the height, h = 50 m

The time taken to lift the mass, t = 2 min

= 120 s

The work done by the crane on the object is equal to the potential energy of the object at that height. It is given by the formula,

W = P. E = mgh joules

Substituting the values in the above equation

W = 900 kg x 9.8 m/s² x 50 m

= 441000 J

The work done by the crane is, W = 441000 J

The power of the crane,

P = W / t

= 441000 J / 120 s

= 3675 watts

Hence, the power of the crane is, p = 3675 watts