Electromagnetic Waves How to make light… Transverse Medium?
The electromagnetic spectrum Continuous spectrum
Basic Concepts v = f v = c = speed of light = 3.00 x 108 m/s f = frequency (Hz) = wavelength (m) 1 nm = 1 x 10-9 m Visible light 700 – 400 nm Atom ≈ 10-10 m Nucleus ≈ 10-15 m
What is the wavelength of a 91.1 MHz radio wave? (2) v = f 1 MHz = 1 x 106 Hz = v/f = (3.00 x 108 m/s)/(91.1 x 106 Hz) = 3.29 m 3.29 m
Ex1 - What is the frequency of a 12.2 cm microwave? (ovens use this) v = f f = v/ = (3.00 x 108 m/s)/(.122 m) = 2.46 x 109 Hz 2.46 x 109 Hz
Ex2 - What is the frequency of a 600. nm light wave? v = f 1 nm = 1 x 10-9 m f = v/ = (3.00 x 108 m/s)/(600. x 10-9 m) = 5.00 x 1014 Hz 5.00 x 1014 Hz