Flywheel – a heavy disk or wheel that is attached to a rotating shaft. Flywheels are used for storage of kinetic energy. The momentum of the flywheel causes it to not change its rotational speed easily. Because of this, flywheels help to keep the shaft rotating at the same speed.

The flywheel has been used since ancient times, the most common traditional example being the potter’s wheel.

• Flywheel using spherical weights in motion. Constructed based on Leonardo da Vinci’s drawings.

In the Industrial Revolution, James Watt contributed to the development of the flywheel in the steam engine.

That’s engineering

• kinetic energy – the energy that moving objects have. Kinetic energy is the energy of movement.