Question

The angular displacement of a simple pendulum is given by $\theta =\frac{\pi }{20}cos(\omega t+\frac{\pi }{6})$ (in radians), where $\omega =2rad/s$. Find length of pendulum.

• A. 2.50 m
• B. 1.60 m
• C. 1.44 m
• D. 6.25 m

Answer 1

The correct option is A 2.50 m

$T=2\pi \sqrt{\frac{l}{g}}$

$\omega =\sqrt{\frac{g}{l}}$

$l=\frac{g}{{\omega }^2}=\frac{10}{4}=2.5m$