A Dynamics Cart is a wheeled vehicle used in physics to teach concepts related to Newton's laws of motion and kinematics. It includes low-friction wheels and accessories such as bumpers, pulleys, and sensors for experiments on forces, acceleration, momentum, and collisions. With inboard wheels, Dynamics Carts are strong and tangle-free. They have low rolling friction and advanced safety features, surpassing other carts. Each pair includes a full pin firing feature and safety catch for accident prevention. This design improves safety when handling carts. Kit Includes: 2 x Dynamics Carts fully assembled and ready to use 1 x Pack of rubber bands for towing the Dynamics Carts 1 x Instruction Sheet *sold in pair Brand: IEC Product Code Type Descriptions Weight Manual SE.MF0945-001 Hyper Fire Cart Low firing 0.6 kg See Here SE.MF0946-001 Non-Firing W/out firing pin 0.45 kg See Here Spare Parts Product Code Item Descriptions SE.PA0945-015 Spare Axle / Front or Rear for trimming the overall weight of 600g SE.PA0945-020 Spare Firing Assembly / Rod & Spring SE.PA0945-050 Spare Wheels with precision low friction bearing SE.PA0945-055 Spare Firing Button with 'O'ring fitted SE.PA0945-060 Spare Steel Locking Ball 7mmD