How fast would a 130 kg person have to run in (m/s) in order to have the same energy as that of a 100w light bulb uses per hour.

Answer 1

Set the kinetic energy of the runner equal to the energy expended by the bulb in 1 hour, and solve for the runner's speed.

mv²/2 = E

v = √(2E/m)

E = (100 w)(3600 s) = 360,000 joules

Plug this value of E (in joules) and the given mass m (in kg) into the equation above for v, and get v in m/s.