Question

A body is projected along a rough horizontal surface with a velocity of 6 m/s. If the body comes to rest after travelling a distance of 9 m, the coefficient of sliding friction is ($g=10m{s}^{-2}$)

• A. 0.5
• B. 0.6
• C. 0.4
• D. 0.2

Answer 1

The correct option is D 0.2

Friction acts as deceleration force on the body,
$ma=\mu mg$
$a=\mu g$

Distance traveled before coming to rest is $9m$.
$v^2-u^2=2as$
$0-6^2=-2\left(\mu g\right)\left(9\right)$
$\mu =\frac{36}{2\times 10\times 9}=0.2$