To demonstrate the cycle of energy change from electrical, via mechanical energy (in the motor) to potential energy (stored in the raised mass), back to mechanical and finally electrical energy used to light the lamp.The shaft extends 50mm beyond the end of the baseboard and is provided with a pair of collars to form the winding drum for the cord.Additional equipment required:6V DC Power Supply (PP00057620)4mm plug connecting leadsHanging masses (500-700g)StringG-Clamp