Question

Two equal forces (P each) act at a point inclined to each other at an angle of ${120}^0$ . The magnitude of their resultant is

• A. p/4
• B. p/2
• C. 2p
• D. p

Answer 1

The correct option is D

p

$R=\sqrt{P^2+Q^2+2Qcos\theta }\Rightarrow R=\sqrt{P^2+P^2+2\left(P\right)\left(P\right)\left(cos{120}^0\right)}=\sqrt{2P^2+2P^2(-\frac{1}{2})}=p$