Question

Among the following, the one that has dimension of the coefficient of friction is

• A. $\left[M^{2} L^{2} T\right]$
• B. $\left[M^{0} L^{0} T^{0}\right]$
• C. $\left[M L^{3} T^{- 2}\right]$
• D. $\left[M^{2} L^{2} T^{- 2}\right]$

Answer 1

Answer: (B)

Limiting friction is given as $f_{l}=\mu _{s}N$
So dimensions of Coefficient of friction is
$\left[\mu _{s}\right]=\left[\frac{f_{l}}{N}\right]=M^{0}L^{0}T^{0}$
So Coefficient of friction is unitless and dimensionless.