Q112 / 197 · NEET 2009 (Mains) · Physics
A simple pendulum performs simple harmonic motion about $\mathrm{x}=0$ with an amplitude a and time period T. The speed of the pendulum at $\mathrm{x}=\mathrm{a} / 2$ will be :
- Correct answerA$\frac{\pi \mathrm{a} \sqrt{3}}{\mathrm{~T}}$
- B$\frac{\pi \mathrm{a} \sqrt{3}}{2 \mathrm{~T}}$
- C$\frac{\pi a}{T}$
- D$\frac{3 \pi^2 a}{T}$
Solution
$\quad \mathrm{v}=\omega \sqrt{\mathrm{A}^2-\mathrm{x}^2}$
$$
=\frac{2 \pi}{\mathrm{T}} \sqrt{\mathrm{a}^2-\frac{\mathrm{a}^2}{4}}=\frac{\pi \mathrm{a} \sqrt{3}}{\mathrm{~T}}
$$
Hence, the correct answer is option: 'A'.