Question

A wave of frequency 500 hertz travel between two points P and Q with velocity 300 metre per second. How many wavelengths are there in PQ if length of PQ is 600 metre?

Answer 1

`1000`

Explanation:

Wavelength is defined by the equation,

`lambda=v/f`

• `v` is the velocity of the waves in meters per second

• `f` is the frequency of the waves in hertz

And so,

`lambda=(300 \ "m/s")/(500 \ "Hz")`

`=0.6 \ "m"`

Since the length of `PQ` is `600 \ "m"`, then there are:

`(600color(red)cancelcolor(black)"m")/(0.6color(red)cancelcolor(black)"m""/"lambda)=1000 \ lambda`

There are `1000` wavelengths in `PQ`.