Question

An object is resting at the bottom of two strings which are inclined at an angle of ${120}^{\circ }$ with each other. Each string can withstand a tension of $20N$. The maximum weight of the object that can be sustained without breaking the strings is

• A. $10N$
• B. $20N$
• C. $20\sqrt{2}N$
• D. $40N$

Answer 1

The correct option is B $20N$


In the horizontal direction, the component of the forces cancel out.

Considering the forces acting in the vertically upward direction, $2T\cos {60}^o=W$

For maximum weight we have,

$2T_{max}\cos {60}^o=W_{max}$

$2\times 20\times \frac{1}{2}=W_{max}$
$W_{max}=20N$
Thus the maximum weight of the object that can be sustained without breaking the strings is 20 N.