Question

Let  A and B be the two vectors of magnitude 10 unit each. If they are inclined to the X-axis at angle 30° and 60° respectively, find the resultant.

Answer 1

 Angle between the vectors θ= 60°-30° =30°. 

Hence magnitude of the resultant = √(A²+B²+2ABcosθ) 

= √(10²+10²+2.10.10.cos30°) 

=√(200+200.√3/2) =10√(2+√3) 

= 19.32 units 

Since the vectors have equal magnitudes so the resultant bisects the angle θ between them. The angle between resultant and vector 

A =30°/2 =15°. So angle between resultant and X-axis =15°+30° =45°.