A stone of mass m tied to the end of a string revolves in a vertical circle of radius R. The net forces at the lowest and highest points of the circle directed vertically downwards are

`T_(1) and v_(1)` denote the tension and speed at the lowest point. `T_(2) and v_(2)` denote corresponding values at the highest point.

Options

A. `{:("Lowest point" ,"highest point"),(mg-T_(1),mg +T_(2)):}`
B. `{:("Lowest point" ,"highest point"),(mg +T_(1),mg -T_(2)):}`
C. `{:("Lowest point" ,"highest point"),(mg +T_(1)-(mv^(2))/(r),mg -T_(2)+(mv^(2))/(r)):}`
D. `{:("Lowest point" ,"highest point"),(mg -T_(1)-(m_(1)v_(1)^(2))/(R),mg +T+(m_(1)v_(1)^(2))/(R)):}`

Answer

a

Explanation

`mg + T_(2) = (mv_(2)^(2))/(R ), T - mg = (mv_(1)^(2))`
Never conface the actual force on a body (tension, force gravety etc) with the effects they produce `ma(mv^(2))/(R )`etc