## College Physics (4th Edition)

We can find the total amount of work that Lars must do: $Work = mgh = (82.4~kg)(9.80~m/s^2)(12.0~m) = 9690~J$ We can find the time it takes to do this work: $t = \frac{Energy}{Power} = \frac{9690~J}{746~W} = 13.0~s$ It will take Lars 13.0 seconds to climb three flights of stairs.