A rocket sled is on a track that goes uphill. The rocket sled starts at rest, at the bottom of the hill, and the rocket is fired. After doing 450 Joules of work on the sled, the sled has a kinetic energy of 200 Joules. Find the gravitational potential energy of the sled at this point.
a. 250 Joules
b. impossible to determine without the mass.
c. 650 Joules
d. 450 Joules
