Friction
principle
A force that resists the relative motion of surfaces.
Where it is used
- Bicycle brake — is used in. Pads press against the rim or disc and shed speed through friction.
- Ball bearing — is used in. A bearing replaces sliding friction with far lower rolling friction.
- Car brake — is used in. Pads press against the disc and shed speed through friction.
- Fire making — is used in. Fire was made by rubbing wood against wood.
- Quern — is used in. Grain is crushed and ground by the friction of the stones.
- Belt drive — is used in. A belt transmits torque through friction.
- Clutch — is used in. Friction discs transmit torque through friction.
- Air brake — is used in. Brake shoes slow the wheels through friction.
- Match — is used in. It lights by friction.
- Teflon — is used in. A very low coefficient of friction.
- Flintlock — is used in. A spark from a strike of flint.
- File — is used in. Material is removed by the friction of the teeth.
- Bow drill — is used in. It drills and lights a fire by friction.
- Sledge — is used in. Low friction of the runners on snow.
- Skis — is used in. Gliding over snow.
- Ice skates — is used in. Very low friction on ice.
- Brake pad — is used in. Friction material.
- Synchromesh — is used in. Friction cones match the speeds.
- Tyre tread — is used in. Grip.
- Coaster brake — is used in. Friction.
- Electrostatic machine — is used in. Friction.
- Abrasive — is used in. Removing material by friction.
- Rope — is used in. Twisted fibres hold each other by friction.
- Millstone — is used in. Grain is ground by friction between the stones.
- Axle — is used in. A wheel turns on its axle, overcoming friction.
- Pile — is used in. A pile is held by friction with the ground.
- Wheellock — is used in. The wheel strikes sparks by friction against pyrite.
- Flanged wheel — is used in. The wheel rolls along the rail.
- Bobsleigh — is used in. Speed is kept up by the low friction of ice.
- Drum brake — is used in. The shoes brake by friction.