A simple pendulum starts oscillating simple harmonically from its mean position ( $\mathrm{x}=0$ ) with…
- $\frac{3 \pi^2 a}{T}$
- $\frac{\sqrt{3} \pi a}{2 \mathrm{~T}}$
- $\frac{\pi a}{\mathrm{~T}}$
- $\frac{\sqrt{3} \pi a}{T}$
Solution
The velocity in simple harmonic motion is given by $v = \omega \sqrt{a^2 - x^2}$, where $\omega = \frac{2\pi}{T}$ is the angular frequency.
At displacement $x = \frac{a}{2}$, the velocity becomes:
$v = \frac{2\pi}{T} \sqrt{a^2 - \left(\frac{a}{2}\right)^2} = \frac{2\pi}{T} \sqrt{a^2 - \frac{a^2}{4}} = \frac{2\pi}{T} \sqrt{\frac{3a^2}{4}} = \frac{2\pi}{T} \cdot \frac{\sqrt{3}a}{2} = \frac{\sqrt{3}\pi a}{T}$
This corresponds to option D.
Asked in: MHT CET 2025 (05 May Shift 2)