Question

10 Calculate angle of friction between wedge and block system is at rest . Coefficient of friction between wedge and block is $\mu$

• A. ${\tan }^{-1}\mu$
  
• B. $2\theta$
• C. $\theta$
• D. $\frac{\theta }{2}$

Answer 1

Answer: (A)

${\tan }^{-1}\mu$

Component of gravity force, $F=mg\sin \theta$

Force of friction, $F_r=\mu mg\cos \theta$ .

For non-skidding condition,

$F_r\ge F$

$\Rightarrow \mu mg\cos \theta =mg\sin \theta$

$\Rightarrow \theta ={\tan }^{-1}\mu$

Hence, angle of friction is ${\tan }^{-1}\mu$ .