Question

A bob of mass `m` connected to the end of an inextensible string of length `l`, is released from position shown in figure. If impacts of bob with smooth floors is perfectly inelastic. Choose the correct options (s)
A. The maximum height reached by the bob during subsequency motion is `(l)/(32)`
B. Maximum height reached by the bob during subsequency motion is zero.
C. Energy loss from the time duration bob is released to the time it reaches at its maximum height during subsequent motion is `(3mgl)/(8)`
D. Energy loss from the time duration bob is released to the time it reaches to the time it reaches at its maximum height during subsequency motion is `(15mgl)/(32)`

Answer 1

Correct Answer - A::D

JBC
Just before string gets taught

Just after string gets taught
Maximum height achieved during sub sequence motion:
`h_(max)=(((v_(2))/(2))^(2))/(2g)=(v_(2)^(2))/(8g)=(1)/(8g)(gl)/(4)=(l)/(32)`
`DeltaE=(mgl)/(2)-(mgl)/(32)=(15mgl)/(32)`