Mousetrap cars

I've only had a bit of experience with mousetrap cars, but have invested a good deal of time using the finite element approach to solve a variety of problems. Thus, I was excited to see such a model used to describe these fascinating and fun devices [William D. Jumper, “Modeling the Mousetrap Car,” Phys. Teach. 50, 137 (March 2012)]. The article continues a tradition of innovative spreadsheet models depicted in The Physics Teacher and describes a valid, inspiring model. However, it should be noted that although the mousetrap car model tracks work and energy, and breaks up a spatial domain into a 1-d grid, it does not approximate a solution to a partial differential equation with basis functions such as simple polynomials. The approach used in this article might be better labeled a finite difference method in work and energy variables.