# VERY BASIC Question on Waves

Since speed = wavelength x frequency, I'd like to know what are the effects of increasing/decreasing the frequency? I know this sounds like a really basic question but I just can't understand it!

Related Introductory Physics Homework Help News on Phys.org
rl.bhat
Homework Helper
Hi MZET, welcome to PF.
The relation " Since speed = wavelength x frequency" is true for a given medium.
Frequency depends on the nature of the source. Speed and hence the wavelength depends on the nature of the medium.
So for a given medium, as frequency increases, wavelength decreases.

The speed of the wave is based on the properties of matter it travels through. I would recommend treating it as constant for a while.
Let's have a theoretical wave with frequency of 1Hz and travelling at 1m/s. What it's wavelength. Now what happens if you double or half the frequency?

If you understood that, you can send you wave through another matters where it travels with say 2 m/s or 0.5 m/s.

If all above done, start travelling yourself. Go 0.5 m/s against and with the 1 m/s wave. How often will you encounter the same phase (e.g. top) of the wave? This is Doppler effect.

Thanks for the answers guys! So does speed always decrease when frequency decreases?

Thanks for the answers guys! So does speed always decrease when frequency decreases?
:)

If you keep wavelength constant, which is about the only value you cannot in real world.