United Scientific Supplies ROLLFRICT Rolling Friction Carts - Set of 4 (5.25" x 2.125" x 1" Each)

This set includes four carts of equal mass, each with wheels made from a different material: soft silicone, soft rubber, wood, and fabric. The free rolling wheels quantitatively demonstrate friction without slipping.

Features:

• Smooth rolling wheels
• Four different materials
• Includes activity guide

Kit includes:

• 4 carts of equal mass
• Activity guide