Question

Two vectors A and B are inclined to each other at an angle theta. Using parallelogram law of vector addition find the magnitude and direction of their resultant.

Answer 1

R=A=B=x

R2=A2+B2+ABcos thetha

X2=x2+x2+x.xcos thetha

X2=2x2+x2 cos thetha

X2-2x2=x2cos thetha

-x2=x2cos thetha

-x2/x2=cos thetha

-1/2=cos thetha

(Cos -1) =cos 60

They have = 60 answer