Question

A uniform sphere of weight $W$ and radius $5\, cm$ is being held by a string as shown in the figure. The tension in the string will be :

• A. $12 \frac{W}{5}$
• B. $5 \frac{W}{12}$
• C. $13 \frac{W}{5}$
• D. $13 \frac{W}{12}$

Answer 1

Answer: (D)

$13 \frac{W}{12}$

Answer 2

$PQ = \sqrt{OP^{2}+OQ^{2}}$
$= \sqrt{13^{2}+5^{2}} = 12$
Tension in the string $T$, so, $Tcos\theta = w$
$\Rightarrow T = \frac{w}{cos\theta} = \frac{13}{12}W$