Definition:Friction/Coefficient/Static

Definition

Let $B$ be a body at rest on a plane surface $S$ on which friction acts.

Let $N$ be the normal reaction of $S$ on $B$.

Let a force be applied to $B$ parallel to $S$

Let $F$ be the magnitude of that force in the limiting case when $B$ is just about to move.

Then the coefficient of static friction is defined and denoted:

$\mu_s = \dfrac F N$

Also see

• Definition:Coefficient of Kinetic Friction

• Results about coefficients of friction can be found here.

Linguistic Note

The word friction comes from the Latin word for rub.

Sources

• 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): coefficient of static friction
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): friction
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): friction
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): coefficient of static friction
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): friction
• 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): friction (frictional force)