Question

At $t=0$ , a transverse wave pulse in a wire is described by the function where $x$ and $y$ are in metre. The function $y\left(\right.x,t\left.\right)$ that describes this wave equation, if it is travelling in the positive $x$ -direction with a speed of $4.5\,ms^{- 1}$ is

• A. $y = \frac{6}{\left(x + 4 \text{.} 5 t\right)^{3} - 3}$
• B. $y=\frac{6}{\left(x - 4 \text{.} 5 t^{2}\right) - 3}$
• C. $y = \frac{6}{\left(x + 4 \text{.} 5 t\right)^{2} - 3}$
• D. $y = \frac{6}{\left(x - 4 \text{.} 5 t\right)^{2} + 3}$

Answer 1

Answer: (D)

$y \left(x \text{,} t\right) = \frac{a}{\left(x \pm v t\right)^{2} + b}$ is another form of progressive wave equation propagating with a speed $v$ . Negative sign to be taken for propagation along $+x-$ axis and positive sign to be taken for propagation along $-$ $x-$ axis.