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In th efigure shown in fig. 10.33 , a bo...

In th efigure shown in fig. `10.33` , a bob attached with a light string of radius `R` is given as initial velocity `u=sqrt(4gR)` at the bottommost point.
(a) At what height string will slack.
(b) What is velocity of the bob just befare slacking of string.

Text Solution

Verified by Experts

The correct Answer is:
B, C
String will slack at height `h_(1)` , discussed in article `10.5` where,
`h_(1)=(u^(2)+gR)/(3g)=(5)/(3)R` , `(as u^(2)=4gR)`
`v=sqrt(u^(2)-2gh_(1))=sqrt(4gR-2gxx(5)/(3)R)`
`=sqrt((2)/(3)gR)`
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Knowledge Check

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