A `1kg` stone at the end of `1m` long string is whirled in a vertical circle at a constant speed of `4m//s`. The tension in the string is `6N`, when the stone is at `(g=10m//s^(2))`

Options

A. (a) At the top of the circle
B. (b) At the bottom of the circle
C. (c) Half way down
D. (d) None of the above

Answer

A

Explanation

`(mv^2)/(R)=(1xx4^2)/(1)=16N`
`mg=1xx10=10N`
`impliesT=mgcostheta+(mv^2)/(R)`
`6=10costheta+16`
`cosec theta=-1`
`theta=-180^@`