Two forces act an angle of 120degre.The bigger force is of 40N and the resultant is perpendicular to the smaller one.Find the smaller force.

Answer 1

draw the diagram.

You can see immediately the resultant is from the componet for Bigger in the direction of R, and that the component of Bigger in the direction of Smaller is =opposite Smaller

40cos30=Resultant
40sin30=Smaller

you can solve for smaller, and resultant from that.