Question

A ball of mass 1 kg hangs in equillibrium from a two strings OA and OB as shown in figure. What are the tensions in strings OA and OB? $(Takeg=10m/s^2)$

• A. $5N,5N$
• B. $5\sqrt{3}N,5\sqrt{3}N$
• C. $5N,5\sqrt{3}N$
• D. $5\sqrt{3}N,5N$

Answer 1

The correct option is C $5N,5\sqrt{3}N$

Apply Lami's theorem at O
$\frac{T_1}{sin{150}^{\circ }}=\frac{T_2}{sin{120}^{\circ }}=\frac{10}{sin{90}^{\circ }}$
$=\frac{10}{1}=10$
$\therefore T_1=10sin{150}^{\circ }=10\times \frac{1}{2}=5N$
$T_2=10sin{120}^{\circ }$
$10\times \frac{\sqrt{3}}{2}=5\sqrt{3}N$.