MCQ
A small block starts slipping down from a point $B$ on an inclined plane $A B,$ which is making an angle $\theta$ with the horizontal section $BC$ is smooth and the remaining section $CA$ is rough with a coefficient of friction $\mu .$ It is found that the block comes to rest as it reaches the bottom (point $A)$ of the inclined plane. If $B C=2A C$, the coefficient of friction is given by $\mu=k \tan \theta$ .The value of $k$ is
  • A
    $13$
  • B
    $8$
  • $3$
  • D
    $17$

Answer

Correct option: C.
$3$
c
Apply work energy theorem

$\operatorname{mg} \sin \theta( AC +2 AC )-\mu mg \cos \theta AC =0$

$\mu=3 \tan \theta$

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