Two forces are such that the sum of their magnitudes is 18 N and their resultant is perpendicular to the smaller force and magnitude of resultant is 12 N. Then the magnitudes of the forces are
13 N, 5 N
A+B=18 ....(i)
12=√A2+B2+2ABcosθ ....(ii)
tan α=B sinθA+B cosθ=tan 90o ⇒=−AB ....(iii)
By solving (i), (ii) and (iii), A=13 N and B=5 N