A nail is located below the point of suspension of a simple pendulum of length 'l'. The bob is released from horizontal position. If the bob loops a verticle circle with nail as centre, find the distance of nail from point of suspension.

A nail is located below the point of suspension of a simple pendulum o

1.	A nail is located below the point of suspension of a simple pendulum of length 'l'. The bob is released from horizontal position. If the bob loops a verticle circle with nail as centre, find the distance of nail from point of suspension.
Answer» Solution :From the PRINCIPLE of conservation of mechanical ENERGY PE at the horizontal POSITION = KE at the lowest position. `mgl = (1)/(20 mv^(2)` To loop the vertical circle `v^(2)= 5G(1-x)` where .x. is the distance of nail from point of SUSPENSION, and .v. is the velocity at lowest point of path. `(mgl = (1)/(2) m.5g (l-x)), l= (5)/(2) (l-x), x= 3l//5`