Question

A crane can lift up 10000kg of coal in 1hour from a mine of 180m depth. If the efficiency of the crane is 80%,its input power must be (take g=10ms)

Answer 1

Answer:

approx 6000 kgm^2/s^3.

Explanation:

1. output power = mgh/t

= (10000×9.8×180)/3600

2. input power = x

3. output power =( 80/100 )x

x = approx 6000.