Question

A simple pendulum is oscillating with an angular amplitude ${60}^0$. If mass of bob is $50gram$, the tension in the string at mean position is:
$(g=10m/s^2)$

• A. $0.5N$
• B. $1N$
• C. $1.5N$
• D. $2N$

Answer 1

Answer: (B)

$1N$

$H=R(1-cos{60}^0)$

$H=\frac{R}{2}$

Apply Work Energy Theorem,

$mg\frac{R}{2}=\frac{1}{2}m{V}^2$

$V=\sqrt{Rg}$

At mean position,
$T-mg=\frac{m{V}^2}{R}$

$T=2mg$

$=2\times 0.05\times 10$
$=1N$