Bob \(B\) of mass \(m\) at rest is hanging vertically from the ceiling by a massless string of length \(10\,\text{m}\), as shown in the figure.
Point mass \(A\) of mass \(m\) travelling horizontally with speed \(10\,\text{m s}^{-1}\) collides with the bob \(B\) elastically.
The bob \(B\) rises to a height \(h\) after the collision.
Taking acceleration due to gravity \(g=10\,\text{m s}^{-2}\) and neglecting the size of the bob, the value of \(h\) is:
