HubbleSite - Reference Desk - FAQs
The relationship between the frequency (the number of wave crests that pass by a certain point in a given amount of time) and wavelength for electromagnetic. It states the mathematical relationship between the speed (v) of a wave and its wavelength (λ) and frequency (f). Using the symbols v, λ, and f, the equation can . see has a particular frequency - Here, the key relationship is shown with worked just a label, or shorthand, in order to allow us to work quickly with the equation. as it is, and there is a calculator for frequency, wavelength and speed here.
Radio waves are just another form of "light", i.
The Wave Equation
Let's say we have a radio with a dial that is only marked in MHz. This is a measurement of frequency and we note that 1 MHz is the same as 1 million hertz the M in MHz stands for " mega ", which means million. We are told of a radio broadcast we want to hear but we are only given the wavelength of the station and not the frequency.The relationship between Wavelength & Frequency
The wavelength we are given is 3. We know the speed of light and we know the wavelength so it's now an easy matter to plug these numbers into the equation and find the frequency of the radio station: This gives us a frequency of 92 MHz, which is found in the FM range of most domestic radios. Visible Light The wavelengths of visible light are measured in nanometres, nm billionths of a metre but the equation works just the same.
When we look at a light source the colours we see are dictated by the frequency of the light. These frequencies are very high by everyday standards.
Have a look around the room and find something that's the colour red. How many times are the tiny crests of the light waves coming from that red object passing through the front of your eyes every second?
In other words, what is the frequency of red light? Well, we know the speed of light and can take an average figure for the wavelength of red light. Let's say it's nm, that is: We now have everything we need to work out the frequency: Newton passed the individual color bands produced by the prism through a second prism.
How are frequency and wavelength related?
This second prism re-combined the individual bands and the light exited the prism as white light. This showed that white light is actually the combination of all of the colors of the spectrum. The color of an object is due to the frequencies and corresponding wavelengths of light absorbed by the object.
Most objects absorb the majority of the frequencies of light. Any frequencies that are not absorbed by the object are reflected, giving the object a particular color. If an object absorbs all light except the frequencies found in the red region of the spectrum, the object appears red.
The Wave Equation
Red light is reflected off of the object. White is actually not a color, but a combination of all colors, occurring when all frequencies of light are reflected.
- Optics - Wavelength, Frequency, And The Speed Of Light
Likewise, black is actually the absence of reflected light, occurring when all frequencies of light are absorbed. Light waves exhibit constructively and destructive interference patterns.
Constructive interference occurs when two or more light waves meet in phase e. When the light waves meet out of phase e.
The concept of interference is important for understanding the phenomena of diffraction. Young's double-slit interference experiment is a classic explanation for diffraction, which is the bending of light as it passes around an object.
Young made two small slits relatively close to each other on a dark board.