A motor with an input power of 100 Watts is connected to a flywheel. How long in units of hours must the motor operate to transfer 300000 joules to the flywheel assuming the process is 80% efficient

Power is the rate of work done given by dividing work done by time. Efficiency is the ratio of work output to work input

power input = 100 watts

power output = x

efficiency = 0.8

thus 0.8 = x/100, therefore x = 80

power is given by energy times time

hence time = 80/300000 = 0.00026 seconds

Time in hours = 0.00026/360 = 7.407 x 10 ∧7 hours