From crest to crest, trough to trough or rest position to rest position
trough to trough crest to crest and its rest position.
This is measured in millimeters and metres.
Measure from crest to crest or trough to trough.
crest to crest
Yards
wavelength
Distance from one crest to the next crest of a wave.
Wave length..
That would depend what information is available. One common equation is: speed = wavelength x frequency. However, in a practical situation, it may be easier to actually measure the wavelength and (for example) the frequency, and then make deductions about the wavelength, than the other way round.
wavelength, amplitude, and frequency
Yes. To be precise, the wavelength is the length of one precise cycle, and one way to measure that is from top to top.
Use a spectrometer to measure the wavelength of the light. There is a direct, but inverse correlation of the wavelength to the temperature.
wavelength
You measure the energy E and divide it into hc. Wavelength w = hc/E = 0.2E-24/Energy.
To measure the speed of a wave, you multiply the frequency by the wavelength.
That will probably vary A LOT, depending on what type of wave you are talking about, and in what range the wavelength is. For example, the ratio between the frequencies - and therefore between the wavelengths - of different electromagnetic waves can be 15 orders of magnitude, or even more - and the techniques used to measure different ranges will certainly not be the same.
Wave length..
Distance from one crest to the next crest of a wave.
use a metre stick
with a scale
divide output by the number of hours worked
Same way it grows in sunlight. Photons of light at the right wavelength impact the pigment chlorophyll, excite and electron from the pigment which then enters photosystem II. Photons of the correct wave length are photons of the correct wavelength and the plant does not care what the source is of these photons.