Intro to Physics Flashcards

Intro to Physics FLASHBACK #1

Key Concepts

• Electromagnetic Spectrum (EM): The full range of electromagnetic radiation, organized by frequency or wavelength.

Electromagnetic Radiation Types

• Types (in order from lowest to highest frequency/energy, and longest to shortest wavelength):
  • Radio waves
  • Microwaves
  • Infrared
  • Visible light
  • Ultraviolet
  • X-rays
  • Gamma rays

Relationships on the EM Spectrum

• Frequency and Wavelength: As frequency increases, wavelength decreases (inverse relationship).
• Frequency and Energy: As frequency increases, energy increases (direct relationship).
• Speed of Light: All radiation on the EM spectrum travels at the speed of light (approximately $300,000,000 \text{ m/s}$).

Wavelength Calculation Example

• Given: A radio wave with a frequency of $2.99 \text{ Hz}$.
• Formula: $\lambda = \frac{v}{f}$, where $\lambda$ is wavelength, $v$ is speed, and $f$ is frequency.
• Calculation: $\lambda = \frac{300,000,000 \text{ m/s}}{2.99 \text{ Hz}} = 100,334,448.16 \text{ m}$

Visible Light Spectrum (Rainbow)

• Colors (from short to long wavelength): Violet, Indigo, Blue, Green, Yellow, Orange, Red

Frequency Definition

• The frequency of a wave is how many times a wave passes a certain point per unit of time.

Comparing Frequencies

• Greater Frequency:
  • Microwaves or radio waves
  • Infrared radiation or UV radiation
  • Gamma rays or x-rays
  • Visible light or Microwaves

Electromagnetic Radiation Technologies

• X-Rays:
  • d. Goes through most matter except bone and lead.
• Microwaves:
  • h. Used in cooking by being absorbed by the water in the food.
  • d. Used to transmit cell phone and Wifi signals.
• Gamma Rays:
  • b. In a hospital, to keep surgical equipment sterile.
• Radio Waves:
  • a. TV broadcast signals.
• Infrared Waves:
  • f. Used for remote controls.
• Ultraviolet Waves:
  • g. The lights used in tanning beds.
• Visible Light:
  • e. Wavelengths and frequencies that the human eye can see.