Question

All the strings shown in the figure are massless. Tension in the horizontal string is $30N$. Find $W$.

• A. $30N$
• B. $50N$
• C. $10N$
• D. $15N$

Answer 1

The correct option is A $30N$

Let the tension in the slanted string and vertical string be $T$ and $T^{\prime }$, respectively.

BY balancing forces in Horizontal direction

we gte: $Tsin45=30$

$⟹T=\frac{30}{sin45}=30\sqrt{2}$ N

And in Vertical direction

we get : $Tcos45=T^{\prime }$

and $T^{\prime }=W$

$\therefore$ $Tcos45=W$

OR $30\sqrt{2}\times \frac{1}{\sqrt{2}}=W$ $⟹W=30$ N