A girl of mass 30kg is jumping at a rate of 30 jumps at 60 sec and each jump to a height of 30 cm. At what rate is she spending energy?

1. 45 W            2. 900 W                 3. 90 W                4. 450 W

 (g = 10 m/s2)

 

Given, 

           mass of  a girl            = 30 kg

           time                           = 60 sec

           number of times        = 30

           Height of each jump = 30 cm