The resultant of two forces acting an anlge of `120^(@)` is 10 kg wt and is perpendicular to one of the forces. That force is

Options

A. `10 sqrt(3)` kg wt
B. `20 sqrt(3)` kg wt
C. 10 kg wt
D. `(10)/(sqrt(3))` kg wt

Answer

D

Explanation

The resultant of `vec F_(1) and vec F_(2)" is "vec R` and it is perpendicular to `vec F_(1)` and R =10 kg wt.
From the figure, `tan 30^(@) =(F_(1))/(R )`
`therefore F_(1) = R tan 30^(@)`
`therefore F_(1) =10 xx (1)/(sqrt(3)) =(10)/(sqrt(3)) kg wt`