Applied Physics LLC develops toys and educational products that are primarily science-oriented. The NewtonCar, the gravity - powered car (US patent 6.773,264) is intended for use at home, in the classroom or for racing competition events. It uses no motors, batteries or fuels, employing only energy weights to power the car from a standing start. It can even climb grades. Change the weights, rear end ratio and wheel types to discover the highest acceleration, highest speed, furthest distance, greatest payload, steepest grade climb!