Question

Bobby does work to climb to the top of a 7 m hill. If Bobby and his sled have a combined mass of 45 kg, howmuch Potential Energy will Bobby have at the top of the hill? (Ignore friction in this problem.)

Answer 1

Take into account that the potential energy is given by the following formula:

U = m·g·h

where

m: mass = 80 kg

g: gravitational acceleration constant = 9.8m/s²

h: height = 7 m

Replace the previous values into the expression for the potential energy U:

U = (80 kg)(9.8 m/s²)(7 m)

U = 5,488 J

Hence, Bobby will have a potential enrgy of 5,844 J when he is a the top of a 7 m hill.