Question

A stone of mass m tied to the end of a string is revolves in a vertical circle of radius R. The net force at the lowest and highest points of the circle directed vertically downwards are : (Choose the correct alternative).
Lowest Point
(a) mg - $T_1$
(b) mg + $T_1$
(c) mg + $T_1$ - $(mv_1{^2})$/R
(d) mg - T1 - $(mv_1{^2})$/R

Highest Point
(a) mg + $T_2$
(b) mg - $T_2$
(c) mg - $T_2$ + $(mv_1{^2})$/R
(d) mg + $T_1$ + $(mv_1{^2})$/R

$T_1$ and $v_1$ denote the tension and speed at the lowest point.
$T_2$ and $v_2$ denote corresponding values at the highest point.

Answer 1

sorry I cannot answer this