Electromagnetic radiation

Last Update: July, 30, 2024 ## BIG IDEAS - Big Idea 1: [[Dual Nature of Light|Wave-Particle Duality]] - Big Idea 2: [[Module 5 Electromagnetic Spectrum|The Electromagnetic Spectrum]] - Big Idea 3: Interaction with Matter ### Definition **Electromagnetic radiation** is the energy being moved by EM waves. Electromagnetic radiation encompasses a wide range of energy waves that travel through space at the [[Speed of Light|speed of light]]. These waves are generated by the [[Notes Vault/Physics Notes Vault/Kinematics/1D Motion/Acceleration|acceleration]] of charged particles and consist of oscillating [[Electric Field|electric]] and [[Magnetic Fields|magnetic fields]]. >[!attention] Light >Light is a specific range of electromagnetic radiation that is visible to the human eye. It is just a small part of the electromagnetic spectrum. \ ### Newton's Contribution - Just as many people before him, [[Notes Vault/Physics Notes Vault/Physicists/Classical Physics/Isaac Newton|Isaac Newton]] separated white light into different colors using a prism. - He originally labeled five color bands red, yellow, green, blue, and violet. - Later he added two colors to match the seven notes of the musical scale and because seven is considered a sacred number. - You can remember the visible colors with the mnemonic ROY G BIV. - There is no wavelength assigned to indigo. - Range of wavelength for visible light is 380 – 750 nm (nm = 1.0 x 10-9 m) - Red is 620-750 nanometers. - Violet is around 380-450 nm. ### Frequency and Wavelength - The key is to remember the relationship between frequency and wavelength in the [[Wave Equation|wave equation]]. $c = \lambda \cdot f$ Where $c$ is the [[Speed of Light|speed of light]] (2.998 x 108 m/s), $\lambda$ is [[Wavelength|wavelength]], and $f$ is the [[Frequency|frequency]] of the wave. >[!tip] The speed of light is a [[Physical constant|physical constant]]. ### Example 750 nanometers is equivalent to 4 x 1014 Hz. - Convert nanometers to meters. - Rearrange the wave equation to isolate frequency ($f$) $f = \frac{c}{\lambda}$ See [[Module 5 Electromagnetic Spectrum]] | [[Dual Nature of Light|Wave-Particle Duality]] --- Return [[Home|Home]] | [[Oscillations]] | [[Waves]] | [[Module 0 Sound]] | [[Electromagnetic radiation]]