Question

The weight of a large steel ball is 14700 Newton’s. What power is used in raising this steel ball to a height of 30 meters if the work is performed in 30 seconds?

Answer 1

W = weight of steel ball = 14700 N

m = mass of steel ball = $\frac{weight}{acceleration due to gravity} =\frac{W}{g} = \frac{14700}{9.8}=1500 kg$

h = height raised = 30 m

Potential energy gained is given as

U = mgh

U = 1500 x 9.8 x 30

U = 441000 J

t = time taken = 30 sec

P = power used

Power is given as

P = $\frac{U}{t}$

inserting the values

P = $\frac{441000}{30}$

P = 14700 Watt