A stone tied to a string rotated with uniform speed in a vertical plane. If the mass of the stone is m, len"gt"h of string is r and the speed of the stone is v, the tension in the string when the stone is at its lowest point is (g = acceleration due to gravity

Options

A. mg
B. `(mv^2)/r`
C. `(mv^2)/r-mg`
D. `(mv^2)/r+mg`

Explanation

Tension,`T=mv^2/r+mgcostheta`
`implies 52=(12xx4^2)/1+(2xx10xxcostheta)`
`costheta=20/20`
`theta=0^0`:.`The stone is at the bottom of the circle when T=52N.