A ball of mass `m=200gm` is suspended from a point `A` by an inextensible string of length `L`. Ball is drawn to a side and held at same level as `A` but at a distance `(sqrt(3))/(2)L` from `A` as shown. Now the ball is released. Then `: (` assume string applies only that much jerk which is required so that velocity along string becomes zero `) `.

Options

A. speed of ball just before experiencing jerk is `sqrt(gL)`
B. speed of ball just after experiencing jerk is `(sqrt(3gL))/(2)`
C. Impulse applied by string `(sqrt(gL))/(10)`
D. ball will experience jerk after reaching to point `B`.

Answer

A, B, C

Explanation

By conservation of energy
`(1)/(2) mv^(2)=mg``(L)/(2)`
`v=sqrt(gL)`
After jerk `v sin theta` becomes zero
Impulse applied by string `=mv sin theta`

`=0.2sqrt(gL)(1)/(2)=(sqrt(gL))/(10)`
velocity of ball after jerk
`v cos theta = sqrt(gL)``(sqrt(3))/(2)=(sqrt(3gL))/(2)`