A pendulum bob is hanging from the roof of an elevator with the help of a light string. When the elevator moves up with uniform acceleration `'a'` the tension in the string is `T_(1)`. When the elevator moves down with the same acceleration, the tension in the string is `T_(2)`. If the elevator were stationary, the tension in the string would be

Options

A. `(T_(1)+T_(2))/2`
B. `sqrt(T_(1)+T_(2))`
C. `(T_(1)T_(2))/(T_(1)+T_(2))`
D. `(2T_(1)T_(2))/(T_(1)+T_(2))`

Answer

A

Explanation

`T_(1)=m(g+a),T_(2)=m(g-a),T=mg`