Question

Two forces equal to P and 2P Newton act on a particle. If the first be doubled and the second be increased by 20 Newton, the direction of the resultant in unaltered. Find the value of P.

Answer 1

The resultant force can be calculated by using parallelogram law of vector addition
Let the two equal forces be F
Then F(resultant)=sqrt(F^2+F^2+2*F*F*cos60°)
F(resultant)=√3F