Product Number: SB31087
In Stock (Ships within 1-2 business days)
The plastic ball rests on the card - when you pull back the spring, the card shoots forward, but the ball returns to its perch on the post. This device illustrates the effect of inertia. To the observer, the ball seems not to have moved at all. Kit contains: plastic ball, stiff card, acrylic base, support post with cone-shaped depression, hardware to attach post and spring to base, and instructions. Grade 6 and up.