`O` is the centre of an equilateral triangle `ABC`. `F_(1), F_(2)` and `F_(3)` are the three forces acting along the sides `AB, BC` and `AC` respectively. What should be the value of `F_(3)` so that the total torque about `O` is zero?

Options

A. `(F_1 + F_2)`
B. `F_1 + F_2`
C. `F_1 - F_2`
D. `(F_1 + F_2)/(2)`

Answer

B

Explanation

(b) Taking torque about `O`, net torque should be zero.
`F_2 xx x - F_3 xx x + F_1 xx x = 0`
`F_3 = F_1 + F_2`.
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