Dynamics: Energy Exchange

A moving wheel

This demonstration shows the energy exchange between several common forms of energy, including gravitational potential energy, kinetic energy, energy loss due to friction and electro-magnetic energy.

Fig. 13-2: A moving wheel showing energy transformation

Two parallel, parabolic plastic tracks supporting an aluminum wheel are shown in Fig. 13-2. Three small magnets are placed on the perimeter of the aluminum wheel. Four batteries are located in the track support and an electro-magnetic field is also provided in the base support.

Place the wheel at one end of the tracks and release it. The wheel rolls towards the middle of the tracks with increasing speed as the potential energy of the wheel changes to kinetic energy. When passing the middle part of the tracks, the wheel speeds up due to a charge of electro-magnetic energy which is sufficient to compensate for the energy loss due to the friction between the wheel and the tracks. The wheel then moves upwards and the kinetic energy is converted to potential energy. When all the kinetic energy is converted, the wheel stops and then starts to roll back down the track for a new cycle of movement. The wheel will continue to roll backwards and forwards along the track as long as sufficient electro-magnetic energy is provided to compensate for the energy loss due to friction.