In the 1950s, an experimental train that had a mass of 2.5 x 10^4kg was powered across level track by a jet engine that produced a thrust of 5 x 10^5N for a distance of 500m. a) find the work done on the train. b) find the change in kinetic energy. c) find the final kinetic energy of the train if it started from rest. d) find the final speed of the train if there was no friction. ok, part A was easy. part b and c confuse me. since the train started at rest, wouldn't the change in kinetic energy be equal to the final kinetic energy? am i missing something very important here or am i just missunderstanding this problem?