Question

Two forces of magnitudes 30, 60 and P Newton acting at a point are in equilibrium. If the angle between the first two is 60⁰, the value of P is –

• A. (a) 25$\sqrt{2}$
• A. (b) 30$\sqrt{3}$
• A. (c) 30$\sqrt{6}$
• A. (d) 30$\sqrt{7}$

Answer 1

(d)

P = $\sqrt{(30)^{2} + (60)^{2} + 2.30.60.\cos 60º}$P =

$\sqrt{900 + 3600 + 1800}$

P = $\sqrt{6300}$ = 30$\sqrt{7}$