Question

A body slipping on a rough horizontal plane moves with a deceleration of $4.0$ $m/s^2$. What is the coefficient of kinetic friction between the block and the plane?

Answer 1

Let the mass be $m$.

Then on the horizontal surface, normal force is $N=mg$.

Hence friction is $f=\mu N=\mu mg$

Hence deceleration is $a=\frac{f}{m}=\mu g$

$⟹\mu g=4⟹10\mu =4$

$⟹\mu =0.4$