The sum of the magnitudes of two forces acting at a point is 18 and the magnitude of their resultant is 12. If the resultant is at 90° with the force of smaller magnitude, what are the magnitudes of forces?
We have, P + Q = 18
and R= 12
Squaring and adding, we get
P2 +R2 = Q2
or Q2 P2 = R2 = 144
Solving Eqs. (i) and (ii) , we get
P = 5 and Q = 13.