Question

A body is moving along a rough horizontal surface with an initial velocity of $10{ms}^{-1}$. If the body comes to rest after travelling a distance of $12m$, then the coefficient of sliding friction will be

• A. $0.5$
• B. $0.2$
• C. $0.4$
• D. $0.6$

Answer 1

The correct option is C $0.4$

Given, $u=10{ms}^{-1}$, $s=12m$, $v=0$
By third equation of motion,
$v^2=u^2-2as$
$0={\left(10\right)}^2-2\times a\times 12$
$24a=100$
$a=4.17{ms}^{-2}$
Coefficient of sliding friction is given by
$\mu =\frac{a}{g}=\frac{4.17}{10}=0.41$