• Describe the Properties of Waves

• Differentiate Between Longitudinal and Transverse Waves

• Understand Wave Behaviors

• Apply the Wave Speed Equation

• Identify Wave Applications in Everyday Life

Learning objective

Waves constantly surround us, from sound and light to infrared and microwaves. Studying waves is crucial in physics to understand how energy transfers without moving matter.

Waves in everyday life

Waves have key features that define them:

• Wavelength: The distance between two adjacent peaks (crests) or troughs in a wave.

• Frequency: The number of complete waves that pass a point per unit time (measured in Hertz, Hz).

• Amplitude: The maximum displacement

  of a particle from its rest position.

• Wave Speed: The distance traveled by

  a wave per unit time (measured in

  meters per second, m/s).

Waves characteristics

Waves can be classified into two main types:

• Longitudinal Waves: The vibrations are parallel to the direction of wave travel. Examples include sound waves and seismic P-waves.

• Transverse Waves: The vibrations are at right angles to the direction of wave travel. Examples include light waves, water waves, and seismic S-waves."

Type of waves

The wave speed, frequency, and wavelength of a wave are related by the equation:

V=fλ

• V: Wave speed (measured in m/s)

• f: Frequency (measured in Hz)

• λ: Wavelength (measured in meters, m)

Example: If a sound wave has a frequency of 300 Hz and a wavelength of 1.13 m, its speed is 339 m/s339 \, m/s339m/s.

The wave equation

Waves exhibit various behaviors when they interact with surfaces and mediums:

• Reflection: Bouncing off a surface, such as sound reflecting off a wall.

• Refraction: Changing direction due to a change in wave speed, like light bending when entering water.

• Diffraction: Spreading out after passing through a narrow gap or around an edge, such as sound waves spreading through an open door.

Wave behaviours

Let’s calculate the frequency of a radio wave:

• Given: Wavelength

  λ=250 m, Speed V=3.0×10^8

• Find: Frequency f

f = V/λ
f = (3.0 10^8) / 250 = 1.2 10^6 Hz

Applications of wave equation

• In summary:

  • Waves transfer energy without transferring matter.

  • Key features include wavelength, frequency, amplitude, and wave speed.

  • Waves can reflect, refract, and diffract, depending on the situation."

Summary of Wave Properties

• Main take away:

  Energy is a way to tranfer energy from one place to the other.

Q&A