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Physics vocabulary · Motion and Forces

Friction

Meaning in physics, with examples

/ˈfrɪkʃən/nounCore term

In physics, friction means: A force that acts between two surfaces in contact and opposes their sliding past each other. It usually turns kinetic energy into heat.

In Turkish: sürtünme, sürtünme kuvveti

How it is used

Physicists distinguish static friction (before sliding starts) from kinetic or sliding friction (during motion), and describe surfaces with a coefficient of friction (μ). Problems often say 'the surface is frictionless' or 'ignore friction'.

Example sentences

  1. The coefficient of friction between the tyre and the dry road is about 0.7.

  2. Without friction, the puck would keep sliding across the ice at a constant speed.

Common collocations

  • coefficient of friction
  • static friction
  • kinetic friction
  • frictionless surface
  • overcome friction
  • forceA push or a pull that can change how an object moves or change its shape. It has both size and direction and is measured in newtons (N).
  • normal forceThe push from a surface on an object that rests on it or presses against it. It always acts at right angles (normal) to the surface.
  • net forceThe single force that has the same effect as all the forces acting on an object together. It is the vector sum of those forces and decides the object's acceleration.
  • energyThe ability of a system to do work or cause change. It comes in many forms, such as kinetic, potential, thermal and chemical, and it is measured in joules (J).
  • efficiencyThe fraction of the energy put into a device that comes out as useful energy. It is given as a decimal or a percentage and can never be more than 100%.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Motion and Forces

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