Question

A block slide down an inclined plane (angle of inclination${60}^0$) with an acceleration g/2. Find the coefficient of kinetic (dynamic) friction.

Answer 1

REF.Image.

$f=\mu N$ $N=mgcos\theta$
$=\mu mgcos\theta$

$ma=mgsin\theta -f$

$ma=m(gsin\theta -4gcos\theta )$

$\frac{g}{2}=gsin\theta -\mu gcos\theta$

$\frac{1}{2}=sin\theta -\mu cos\theta$

$\frac{1}{2}=\frac{\sqrt{3}}{2}-\mu \times \frac{1}{2}$

$1=\sqrt{3}-\mu$

$\mu =\sqrt{3}-1$

$=173-1=0.73$