Question

A stone of mass \(10\,\text{g}\) is attached to a string of length \(80\,\text{cm}\) and is rotated in a horizontal circle at a height of \(h\) from the ground with a centripetal acceleration of \(125\,\text{m s}^{-2}\). At a moment the string breaks and the stone strikes the ground at a horizontal distance of \(10\,\text{m}\). Then the value of \(h\) is \[ (\text{Acceleration due to gravity}=10\,\text{m s}^{-2}) \]

• A. \(10\,\text{m}\)
• B. \(5\,\text{m}\)
• C. \(15\,\text{m}\)
• D. \(20\,\text{m}\)

Hint:

For a body projected horizontally, \[ \boxed{x=vt,\qquad h=\frac12gt^2.} \] First find the horizontal speed from centripetal motion and then use projectile motion equations.

Answer 1

The Correct Option is B