The mousetrap car project is a classic physics challenge: Build a vehicle that can travel as far as possible by using only the energy from a single mousetrap. Seems simple enough, but the reason it's so popular is because it's rich in science concepts, applied math, and design possibilities. This is what the High School Science classes choose as their make-up project for the two weeks we missed school.
This is an engineering activity that requires students to build a mousetrap car based on certain constraints. Constraints include students having a specified power source for their vehicle; the mousetrap, the car having specified maximum dimensions, and a minimum required distance of five meters that the car must travel. The activity does a great job of requiring students to consider trade offs, design a solution, test their design, make changes in their design, and then make a final decision about their solution based on data and performance.