Question

A sound wave of frequency $500\text{Hz}$ covers a distance of $1000\text{m}$ in $5\text{s}$ between points $x$ and $y$. Then the number of waves between $x$ and $y$ are

• A. 5000
• B. 2500
• C. 100
• D. 500

Answer 1

Answer: (B)

2500

$\nu =500\text{Hz}$

$x=1000$

$t=5\text{s}$

velocity of sound $v=\frac{x}{t}=200\text{m/s}$

But $v=\nu \lambda$

Hence, $\lambda =\frac{2}{5}\text{m/s}$

Now $n\lambda =x\text{or}n=2500$

Ans: B