This project was based on the Next Generation Science Standard MS-PS2-2: “Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.” In general, it is a good fit for disciplinary core idea PS2.A (Forces and Motion). For younger students, this project could meet Common Core math standards for division (4.OA.A, 4.NBT.B, and 5.NBT.B) or fractions (4NF.B and 5.NF.B). Including gears in this project would align it with Common Core math standards for proportions (6.RP.A, 7.RP.A, and 8.EE.B).