A bob hung from the ceiling of a room by a string is performing simple harmonic oscillations. What will be the trajectory of the bob, if the string is cut. When bob is (i) at one of its extreme positions (ii) at its mean position ?

Explanation

Here A and C are extreme positions of the bob and B is its mean position .
(a) If the bob is it at A or C when the string is cut , the bob will fall straight , vertically downwards . This is because when the bob is at extreme position , it is momentarily at rest . If at this point the string is cut , it will simply be a case of a body falling freely under gravity .
(b) If the bob is at B when tyhe string is cut , the bob will follow a parabolic path. This is because when the bob is at its mean position , it has a velocity along horizontal direction . If at this point the strintg is cut , it will simple be a case of a projectile fired horizontally