A bob of mass 0.1 kg hung from the ceiling of a room by a string 2m long is set into oscillation. The speed of the trajectory of the bob if the string is cut when the bob is (a) at one of its extreme positions, (b) at its mean position.

Explanation

(a) We know that at each extreme position, velocity of the bob is zero. If the string is cut at the extreme position, it is only under the action of .g.. Hence the bob will fall vertically downwards.
(b) At the mean position, velocity of the bob is 1 m/s. along the tangent to the arc, which is in the horizontal direction. If the string is ut at mean position, the bob will behave as a horizontal projectile.