MCQ
Find minimum height of obstacle so that the sphere can stay in equilibrium. 
  • A
    $\frac{R}{{1 + \cos \theta }}$
  • B
    $\frac{R}{{1 + \sin \theta }}$
  • C
    $R (1- sin\theta )$
  • $R (1 - cos\theta )$

Answer

Correct option: D.
$R (1 - cos\theta )$
d
The sphere is on the verge of toppling when a line of action of weight passes through the edge. The equilibrium is because of the line of action of weight and the normal reaction provided by the edge.

$\cos \theta=\frac{(R-h)}{R}$

or

$h=R-R \cos \theta$

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