Supertek Dynamic Mini-Carts, Set of 2

For experiments in velocity, acceleration, momentum, elastic collisions, and more! Learn by using this Dynamic Carts Set. The plastic cars have deep wells for additional masses, includes two rubber bumpers for inelastic collisions, two spring loops for elastic collisions and instructions. Each measure 5-1/8" x 2" x 1-3/8".   Special Shipping Information:  This item ships separately from other items in your order.  This item cannot ship to a P.O. Box.  This item may be subject to additional processing days.   Item is not eligible for expedited shipping.    You may initiate a return for unused items within 30 days, if the items are in original packaging with all original materials included with the shipment.