Question

A block is gently placed at the top of a inclined plane 6.4 m long. Find the time taken by the block of slide down to the bottom of plane. The plane makes an angle 30 with the horizontal. coefficient of friction between the block and the plane is 0.2. [ g = 10$m$\$se{c}^2$]

Answer 1

From FBD acceleration can be claculated as

$a=\frac{mg\sin \theta -\mu mg\cos \theta }{m}=g\sin \theta -\mu g\cos \theta$

$⟹a=3.267m/s^2$

from equation of motion $s=ut+\frac{1}{2}a{t}^2,$

where u= initial velocity=0

$6.4=\frac{1}{2}\times 3.267\times t^2$

$⟹t=1.979$