A main revolves a stone of mass `m` tied to the end of a string in a circle of radius R The net force at the lowest and beight point of the circle directed vertical downward are
Here`T_(1),T_(2)` and `(v_(1),v_(2))` denote the tension in the string (and the speed of the stone) at the lowest and highest points, respectively.

Options

A. `mg-T_(1)` and `mg+T_(2)`
B. `mg+T_(1)` and `mg-T_(2)`
C. `mg+T_(1)-((mv_(1)^(2))/(R))` and `mg-T_(2)+((mv_(2)^(2))/(R))`
D. `mg-T_(1)-((mv_(1)^(2))/(R))` and `mg+T_(2)+((mv_(2)^(2))/(R))`

Answer

A

Explanation

At the lowest point, mg acts downwards and `T_(1)` upwards so that net force `=mg-T_(1)` .
At the highest point, both mg and `T`, act downwards so that net force `=mg+T_(2)` .
Hence, option (a) is correct.