So i have decided for my physic project to build a magnetic linear accelerator made with half inch ball bearings on a plastic track. The first bearing is rolled and accelerated by the magnet which when struck, launches the ball on the other side due to the momentum of the accelerated bearing. However my problem is which type of magnets should i use? I need something powerful so obviously it should be a Neodymium magnet but ive heard rumors that the magnets mass needs to be about equal the mass of the ball bearings to facilitate easy transfer of energy from the ball striking to the one behind the magnet. Is this true? And can anybody alert me of other pitfalls to watch fro when picking magnets for this project? Thanks for the support.