An ideal way of demonstrating how a force such as friction can slow down a moving object. There are 3 different surfaces in total, including: carpet, smooth MDF and hardboard. The angle of the slope can be varied in 9 positions and weights can be added to the truck to show how this affects speed. Frame: 530mm x 230mm. Ramp: 330mm x 995mm. Double-sided ramp with wooden truck. .