Q161 / 180 · COMEDK 2013 · Physics

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

  • A
    $P / 2$
  • B
    $P / 4$
  • Correct answer
    C
    $P$
  • D
    $2 P$

Solution

The magnitude of resultant of two forces is given by $R=\sqrt{A^{2}+B^{2}+2 A B \cos \theta}$ Given, $\quad A=B=P$ and $\theta=120^{\circ}$ $\therefore \quad R=\sqrt{P^{2}+P^{2}+2 P^{2} \cos 120^{\circ}}$ $=\sqrt{2 p^{2}\left(1-\frac{1}{2}\right)}=p$

Hence, the correct answer is option: 'C'.

Relevant Questions