Electromagnetic Waves

Symbols

• c - speed of light (3.0 × 10⁸ m/s)
• λ - wavelength
• v - frequency
• h - Planck’s constant

Formulas

• speed of light = wavelength × frequency (c = λ × v)
• energy = Planck’s constant × frequency (E = h × v)

Measurement units

• speed of light - m/s (meters per second)
• wavelength - nm or m (nanometers or meters)
  • 1 meter is 1 billion (1,000,000,000) nanometers
  • nano sounds like nine; 1 billion has nine zeros
• frequency - Hz (hertz)
• Planck’s constant - kg/s (you do not need to know this)

Definitions

• wavelength - the distance between two adjacent crests or troughs on a wave
• frequency - the number of waves that pass the same point in a specific amount of time
• electromagnetic waves - waves that consist of vibrating electric and magnetic fields
  • electromagnetic radiation - the transfer of energy by electromagnetic waves
• light - a form of energy that behaves as both a particle and a wave
  • photon - a particle of light or electromagnetic radiation

Wavelength and frequency have an inversely proportional relationship (as wavelength increases, frequency decreases, and vice versa).

Frequency and energy have a directly proportional relationship (as frequency increases, energy increases, and vice versa).

Electromagnetic spectrum

• Seven types of electromagnetic radiation in total

• Light waves include infrared, visible light, and ultraviolet rays