A car of mass 2000 kg is lifted up a distance of 30 m by a crane in 1 min. A second crane does the same job in 2 min. Do the cranes consume the same or different amounts of fuel ? What is the power supplied by each crane ? Neglect Power dissipation against friction.
t1 = 1 min = 60 , t2 = 2 min = 120
W = Fs = mgs = 5·88 × 105 J
As both cranes do same amount of work so both consume same amount of fuel.
∴ P1 = 9800 W & P2 = 4900 W.
