Two equal forces (P each) act at a point inclined to each other at an angle of `120^(@)`. The magnitude of their resultant is

Options

A. P/2
B. P/4
C. P
D. 2P

Answer

C

Explanation

Resultant vector `|vec(R)| = sqrt(A^(2) + B^(2) + 2AB cos theta)`
`rArr |vec(R)| = sqrt(p^(2) + P^(2) + 2P^(2) cos 120^(@))`
`rArr sqrt(2P^(2)+ 2P^(2) (-(1)/(2))) [ because cos 120^(@)= - (1)/(2)]`
`rArr P`