Pasco Collision Carts with built-in magnets reduce the energy lost duirng collision by applying a magnetic repulsion force during the collision.
Cart 1 is 1500 g while Cart 2 is 500 g. Conservation of momentum is applicable, because the force of collision is much higher than the friction. Hence we can assume that there is negligible net external force.
Author: Leong Tze Kwang, Lim Beng Choo