A child sits in a sled on a horizontal snowy surface. The
combined mass of the child and the sled is 20 kg. The kinetic coefficient of
friction is 0.39. Initially the child and her sled are at rest.
After you pull the sled 9 m the velocity of the sled is 1.5 m/s. How much
total mechanical work (J) did you do as you pulled the sled and child 9 m?