Q123 / 180 · AIIMS 2013 · Physics
A simple pendulum performs simple harmonic motion about $x=0$ with an amplitude ' $a$ ' and time period ' $T$ '. The speed of the pendulum at $x=a / 2$ will be
- A$\frac{\pi a}{T}$
- B$\frac{3 \pi^2 a}{T}$
- Correct answerC$\frac{\pi a \sqrt{3}}{T}$
- D$\frac{\pi a \sqrt{3}}{2 T}$
Solution
As simple pendulum performs simple
harmonic motion.
$\therefore$ velocity, $v=\omega \sqrt{a^2-x^2}$
At, $x=\frac{a}{2}$
$v=\frac{2 \pi}{T} \sqrt{a^2-\left(\frac{a}{2}\right)^2}=\frac{2 \pi}{T} \frac{\sqrt{3 a^2}}{2}=\frac{\pi a \sqrt{3}}{T}$
Hence, the correct answer is option: 'C'.