The Spring Cart Launcher provides an economical way to launch carts in a repeatable fashion. It can be used for Hooke’s Law, collisions, and for Conservation of Energy. It fits into the bed of a Dynamics Cart or PAScar. To launch the cart, the plunger is pulled through the hole in the new endstop, compressing the spring, and then released. To add repeatability, a second endstop can be used with the supplied pin to hold the plunger at a specified compression position. Three different strength springs are provided with the Spring Cart Launcher. Use with or without probeware.