Question
A 660Hz tuning fork sets up vibration in a string clamped at both ends. The wave speed for a transverse wave on this string is 220m/s and the string vibrates in three loops.
  1. Find the length of the string.
  2. If the maximum amplitude of a particle is 0.5cm, write a suitable equation describing the motion.

Answer

Frequency of the tuning fork, $\text{f}=660\text{Hz}$

Wave speed, $\text{v}=220\text{ms}$

$\Rightarrow\lambda=\frac{\text{v}}{\text{f}}=\frac{1}{3}\text{m}$

No.of loops = 3

  1. So, $\text{f}=\Big(\frac{3}{2\text{l}}\Big)\text{v}$

$\Rightarrow\text{l}=50\text{cm}$

  1. The equation of resultant stationary wave is given by

$\text{y}=2\text{A}\cos\Big(\frac{2\pi\text{x}}{\text{Ql}}\Big)\sin\Big(\frac{2\pi\text{vt}}{\lambda}\Big)$

$\Rightarrow\text{y}(0.5\text{cm})\cos(0.06\pi\text{cm}^{-1})\sin(1320\pi\text{s}^{-1})$

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