Put the sail in place, and the cart stays still. Remove the sail, and watch it go! This inexpensive tool is perfect for opening up a discussion of Newton's laws of motion, inertia, acceleration, and action-reaction.  A great value piece of equipment that is affordable for any classroom.

We even include a clip that allows you to vary between one and two batteries, and measure the differences in acceleration with different magnitudes of net force.

The cart size is: 140mm x 70mm x 130mm. Sail Measurements: 110mm x 105mm.
Fan style and color may vary. Requires two AA batteries, not included.