Question

A sound wave of frequency $245\, Hz$ travels with the speed of $300 \,ms ^{-1}$ along the positive $x$ -axis. Each point of the wave moves to and fro through a total distance of $6 \,cm$. What will be the mathematical expression of this travelling wave ?

• A. $Y ( x , t )=0.03\left[\sin 5.1 x -\left(0.2 \times 10^{3}\right) t \right]$
• B. $Y ( x , t )=0.06\left[\sin 5.1 x -\left(1.5 \times 10^{3}\right) t \right]$
• C. $Y ( x , t )=0.06\left[\sin 0.8 x -\left(0.5 \times 10^{3}\right) t \right]$
• D. $Y ( x , t )=0.03\left[\sin 5.1 x -\left(1.5 \times 10^{3}\right) t \right]$

Answer 1

Answer: (D)

$\omega=2 \pi f$
$=1.5 \times 10^{3}$
$A=\frac{6}{2}=3\,cm =0.03\,m$