What is the speed of a wave

# What is the speed of a wave - mm 10-3 Infrared Centimeter...

This preview shows pages 1–2. Sign up to view the full content.

What is the speed of a wave? Imagine you are on the beach watching the ocean waves go by, and you want to know the speed of the waves. There is an island offshore with a palm tree that will serve as a convenient frame of reference. You count the number of waves that pass by the tree in one minute: In this case, two peaks (two wavelengths) pass by the tree in one minute. Thus, the frequency is 2 wavelengths/minute. If we measure the distance between the peaks (i.e. the wavelength) we can determine the speed of the wave: Speed of the wave = (distance between peaks) * (frequency) = (wavelength) * (frequency) The unit of length chosen to describe a particular wavelength is typically dependent on the type of electromagnetic radiation Unit Symbol Length (m) T Angstrom Å 10 -10 X-ray Nanometer nm 10 -9 UV, visib Micrometer m 10 -6 Infrared

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Millimeter
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mm 10-3 Infrared Centimeter cm 10-2 Microwa Meter m 1 TV, radio The range of EM wavelengths is dramatic • The wavelengths of gamma-rays (<0.1 Å) are similar to the diameter of atomic nuclei • The wavelengths of some radio waves can be larger than a football field Frequency • Frequency is expressed in cycles per second , also known as hertz ( Hz ) • Usually the dimension 'cycles' is omitted and frequencies thus have the dimension of s-1 Sodium vapor lamps are sometimes used for public lighting. They give off a yellowish light with a wavelength of 589 nm. What is the frequency of this radiation? frequency*wavelength = speed of light frequency = speed of light/wavelength = (3.00x10 8 m/s)/(589x10-9 m) = 5.09 x 10 14 s-1 = 5.09 x 10 14 cycles per second or 5.09 x 10 14 hertz...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

What is the speed of a wave - mm 10-3 Infrared Centimeter...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online