Energy Transformations in a Ferris Wheel

Physics of the Giant Wheel

A Ferris wheel elegantly demonstrates mechanical energy conversion driven by electrical input.

1. Electrical → Mechanical (Motor)

An electric motor (typically AC induction with gearbox) draws power from the grid. It applies torque to the rim or central hub, doing work against gravity to lift cabins.

2. Gravitational Potential Energy (GPE) ↑

As cabins rise, GPE = mgh increases. At the top (max height), GPE is maximal; kinetic energy (KE) minimal (near zero if constant speed).

3. GPE → Kinetic Energy (KE) ↓

Descending cabins convert GPE back into KE. At the bottom, speed peaks (max KE), GPE minimal. In ideal frictionless case, total mechanical energy conserved.

4. Real-World Losses

• Friction (bearings, gear mesh) → heat.
• Air resistance on cabins.
• Motor inefficiency (electrical → heat + mechanical).

Continuous motor input compensates losses, maintaining steady angular velocity.

5. Regenerative Potential

Modern wheels could use regenerative braking (motor as generator during descent) to feed power back to grid—rarely implemented due to cost/complexity.

Summary

Electrical → Mechanical (motor) → GPE (ascent) ↔ KE (descent) + Heat (losses). A beautiful, large-scale physics demo you can ride.