Methods to Reduce Friction

Friction is not purely a nuisance — it is essential for walking, for vehicles to move (tyre-road friction), and for braking systems (kinetic friction between brake pads and wheel). But in machines, friction between moving parts wastes energy as unwanted heat and causes wear. Two standard methods reduce it:

1. Lubricants (oil, grease) — placed between two surfaces in relative motion, they reduce direct solid-solid contact, cutting down kinetic friction substantially.
2. Ball bearings — inserted between two surfaces, they convert the (large) kinetic/sliding friction of the relative motion into the much smaller rolling friction of the balls, protecting machine parts from wear over long use. …