Lesson 7: Electromagnetic and Mechanical Waves
Understanding Electromagnetic and Mechanical Waves
Electromagnetic waves do not need a medium to travel through and can travel through the vacuum of space. Mechanical waves need a medium to travel through.
Electromagnetic waves include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Mechanical waves include sound waves, water waves, and seismic waves.
Example Problems
Example problem:
A sound wave traveling through the air has a frequency of 500 Hz and a speed of 340 m/s. What is the wavelength of the sound?
Solution:
Wavelength = Speed / Frequency
= 340 m/s / 500 Hz
= 0.68 m
Another example:
Calculate the speed of a light wave with a wavelength of 600 nm (nanometers).
Solution:
Speed of light (c) = Wavelength * Frequency
= 600 nm * Frequency
Frequency = Speed of light / Wavelength
= 3.00 * 10^8 m/s / 600 * 10^-9 m
= 5 * 10^14 Hz