The motion of an object in a loop without friction is a classical example of normal acceleration problems with non-uniform circular motion and of energy conservation laws in Introductory Physics Courses. However, in real life toy car set-ups, friction becomes an important ingredient to determine whether a car will run beyond the top of the loop or not.

This experiment analyzes the motion of a toy car in a loop with a dynamical model that considers the action of three forces: gravity (mg), Normal Force (N) and Friction (FR). A Cartesian coordinate system is used, with its origin at the initial point of the trajectory, at the bottom of the loop. The simulated trajectory obtained with Tracker Dynamic particle (Cartesian) model is compared with the experimental trajectory data from a slow motion video.