Rolling friction car kit, provides four cars for exploration into the force of friction, Each car provides a set of different material wheels (wood, fabric, soft rubber, soft silicone), Weight (lb): 1.0, Length (in):5.8, Width (in):6.5, Height (in):3.5
Harmonic Motion Spring, ideal for demonstrations or hands on experiments in the physics classroom, 7 inches (18 cm) long with a maximum diameter of 1.4 inches (3.5 cm) and a spring constant (k) of 9.6 N/m