Key Definitions to Understand Wave Motion

Wave motion is an important topic in physics, especially when studying waves and sound. Here are some key terms and ideas to help you understand better:

1. Wave

A wave is a movement that carries energy from one place to another. This happens without permanently moving the material it travels through. Waves can move through different things, like solids, liquids, and gases.

2. Medium

The medium is the material that a wave travels through. For example, air is the medium for sound waves, while water is the medium for waves you see in the ocean.

3. Types of Waves

There are two main types of waves:

• Transverse Waves: In these waves, the particles of the medium move up and down while the wave itself moves side to side. An example is a wave on a string or light waves. Here are two important parts:
  • Crest: The highest point of the wave.
  • Trough: The lowest point of the wave.
• Longitudinal Waves: In these waves, the particles move back and forth in the same direction as the wave. Sound waves are a good example. Here are two key parts:
  • Compression: Areas where particles are close together.
  • Rarefaction: Areas where particles are spread out.

4. Wavelength (λ)

Wavelength is the distance between two consecutive crests or troughs in a transverse wave. In a longitudinal wave, it’s the distance between compressions. We usually measure it in meters (m).

5. Frequency (f)

Frequency is how many wave cycles pass a certain point in a specific amount of time. We measure frequency in Hertz (Hz). One Hertz means one wave cycle every second.

6. Amplitude (A)

Amplitude is the highest distance from the wave's rest position to its crest or trough. It shows how much energy the wave carries. A higher amplitude means more energy.

7. Wave Speed (v)

Wave speed tells us how quickly a wave travels through its medium. We can find it using this formula:

$$v = f \cdot \lambda$$

In this formula, $v$ is the wave speed, $f$ is the frequency, and $\lambda$ is the wavelength.

By understanding these key definitions, you can have a strong base for learning more about wave motion in physics.