Lesson 01 - Intro to Waves and Transverse Waves May 7, 2020

Frequency

  • Frequency is the number of complete cycles per unit time.

  • Physicist definition: f=cycless=Hzf = \frac{cycles}{s} = Hz

  • Units: s−1s^{-1} or Hz (Hertz)

  • 60 Hz is mentioned.

  • Formula: f = \frac{\text{# of cycles}}{\text{time}}

  • Example 1:

    • A mass suspended from the end of a spring vibrates up and down 24 times in 36 s. What are the frequency and period of the vibration?

    • Number of cycles = 24 cycles

    • Time = 36 s

    • Frequency = 24 cycles36 s=0.67 Hz\frac{24 \text{ cycles}}{36 \text{ s}} = 0.67 \text{ Hz}

Transverse Waves

  • The wave (energy) moves perpendicular to the direction of the particles.

Wavelength (λ\lambda)

  • Represents 1 cycle

  • The length of the wave in meters.

  • Distance between 2 successive identical points in meters.

  • Peak/maximum/crest: Represented visually.

  • Equilibrium: Zero point, not moving.

  • Valley/minimum/trough: Represented visually. Not moving.