A child has two red wagons, with the rear one tied to the front by a stretchy rope (a spring). If the child pulls on the front wagon, the ____ increases.
(a) kinetic energy of the wagons
(b) potential energy stored in the spring
(c) both A and B
(d) not enough information

Video Transcript

This is College Physics Answers with Shaun Dychko. When the child pulls on this front wagon, it'll cause the spring to stretch and so by stretching it's going to then contain some elastic potential energy. The kinetic energy of this front wagon is also going to be increasing because they're making it go faster and faster directly by pulling it. So the answer is C, both A and B are true. Both kinetic energy of the wagons and the potential energy stored in the spring will increase.