Energy, work and power

The ride is simulated: a 500 kg car with its riders, a straight lift hill 40 m long and 20 m high, a second hill 12 m high, and g = 9.8 N/kg. The chain pulls with a steady 2450 N, the part of the car’s weight along the slope, at 1.0 m/s or 2.0 m/s. The lift is modelled without friction, so the chain’s 98 kJ of work all goes into the gravitational potential store, and the car’s small kinetic energy on the moving chain is left out.

On the ideal track nothing rubs until the brakes. On the real track, friction and air resistance are one steady 200 N force against the motion all the way round, so the thermal store grows by 200 J for every metre. Real air resistance grows with speed. The energy of the spinning wheels is left out.

The lift is shown 4 times faster than real time and the free ride slowed to 0.7 times real speed. Each new ride starts the bars from zero: the warmth from the last ride has spread into the surroundings.

With reduced motion each run happens at once: the car goes straight to the top of the lift hill or into the brakes, and the bars, the clock and the speed sensor show their final readings.