Lars, of mass 66.1 kg, can do work for about 2.00 min at the rate of 1.00 hp (746 W). How long will it take him to climb three flights of stairs, a vertical height of 15.0 m? Express your answer in seconds.

The answer to the question is;

To climb three flights of stairs, a vertical height of 15.0 m will take Lars 13.04 s.

Explanation:

To solve the question, we note that

Mass m of Lars = 66.1 kg

Rate of doing work, power of Lars = 746 W = 746 J/s = Energy/time

Height of the stairs = 15.0 M

Energy required  = Potential energy gained at top of stairs = m×g×h

m×g×h = 66.1 kg×9.81 m/s²×15 m = 9726.615 J

Therefore the time required = Energy/Power = 9726.615/746 = 13.04 s

It take Lars 13.04 s to climb three flights of stairs, a vertical height of 15.0 m

+15-35=-20

going in opposite directions