If one station broadcasts at 90.5 MHz and another one at 107.1 MHz which stations signal has waves with longer wavelengths?

1 Answer
Mar 9, 2018

90.5 MHz will have the longer wavelength.

Explanation:

The formula relating frequency, #f#; wavelength, #lambda#; and transmission speed, #v#, is

#v = lambda*f#

You don't need to memorize this. Remember what the SI units are for each of those and get the equation to balance.

SI units:

the frequency unit is #1/s#
the wavelength unit is #m#
the velocity unit is #m/s#

The velocity is the one with the most complicated units so start with that:

#v = ?#

You need the units you plug into whatever is on the right side of the equal sign to give you #m/s# and you have not used #f and lambda# yet. So, it looks like

#v = lambda*f#

will do the job.

The velocity is fixed. So the choice is between 90.5 MHz and 107.1 MHz. Which will give you a numerically larger lambda?

I hope this helps,
Steve