Question

A simple pendulum is oscillating with an angular amplitude ${30}^o$. If mass of its bob is 50g. The tension in the string at its mean position ($g=10m/s$${}^2$)

• A. $0.634N$
• B. $0.317N$
• C. $1.268N$
• D. $0.433N$

Answer 1

The correct option is A $0.634N$

at dreamer position T=mg cos$\theta$
$\frac{1}{2}m{v}^2=mgL(cos\theta -\theta )$
$T-mgcos\theta =\frac{m{V}^2}{L}$
$T-mgcos\theta =2mg(cos\theta -cos\theta )$
$T=3mg\cos \theta -2mgcos\theta$
$\theta ={30}^o$
$\therefore T=3mg-2mgcos{30}^o$
$T=0.634N$