A pendulum is made by attaching a ball at the end of a string (the other end of the string is attached to the ceiling). The ball is released from rest at the position shown at some angle `phi`. Which of the following vectors may represent the impulse delivered by the string to the ball from the time it is released unitl the ball is at the bottom of the swing when string becomes vertical

Options

A.
B.
C.
D.

Answer

B, C, D

Explanation

`a_(y)=(d^(2)h)/(dt^(2))= - 3m//s^(2)`
Let acceleration of block is `a_(b)` and incline is `a_(1)`
`a_(bi)=a_(b)-a_(i)impliesa_(b)=a_(bl)+a_(1)`
`a_(bi) sin 30^(@)=3`
`a_(bi)=6`
as momentum can be conserved in horizontal (x) direction.
So, `m(a_(bl) cos 30^(@)-a_(1))=ma_(i)`
`implies 2a_(l)=a_(bi)(sqrt(3))/(2)impliesa_(i)=(3sqrt(3))/(2)`