Question

A source of frequency $500Hz$ emits waves of wavelength $0.2m$. The time the wave takes to travel a distance of $300m$ is :

• A. 75 seconds
• B. 60 seconds
• C. 12 seconds
• D. 3 seconds

Answer 1

Answer: (D)

3 seconds

We have , speed of wave , $v=n\lambda$ ,

where $n=$ frequency of wave ,

$\lambda =$ wavelength of wave ,

given $n=500Hz,\lambda =0.2m,d=300m$ ,

hence $v=500\times 0.2=100m/s$ ,

therefore , time taken to cover a distance of 300m ,

$t=d/v=300/100=3s$