The motor of a crane uses power p to lift a steel beam.

P = mgh / t
P ‘ = mg 2h / [ t/2 ] = 4 mgh / t = 4 P
4 times
We know that
Power = workdone / time
= m g h /
t
Now
P ‘ = m g h’ / t’
Given that h’ = 2 h

t’ = t / 2
Therefore
P ‘ = m g 2h / t/2
= 4
m g h / t
= 4
P
Therefore power increases by four times of intial power
general formula–>P = mgh / t
changed power P ‘ = mg 2h / [ t/2 ] = 4 mgh / t = 4 P
hence,factor must be increased by factor 4.