What is a Wave?
| Definition: Wave |
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| A wave is a disturbance that propagates through space, transferring energy with it but not matter. |
- It carries energy away from the wave source.
- It transfers energy without transferring matter.
| What is a Wave? (Pennsylvania State University) [website] |
| Types of Wave [YouTube video] |
Longitudinal & Transverse waves
- Longitudinal waves are waves which travel in a direction parallel to the direction of vibrations.
- Transverse waves are waves which travel in a direction perpendicular to the direction of vibrations.
| Longitudinal and Transverse Wave Motion (Pennsylvania State University) [website] |
Mechanical & Electromagnetic Waves
- If atoms (matter) are involved then the wave will be a mechanical wave.
- A type of wave that travels without the need for matter is an electromagnetic (em) wave.
Vibrations in ropes
- One end of a horizontal rope can be moved up and down to generate waves which travel along the rope to the other end. This produces transverse waves. This is a type of mechanical wave.
Vibrations in springs
- One end of a horizontal spring (e.g. slinky spring) can be moved up and down to generate waves which travel along the rope to the other end. This produces transverse waves.
- One end of a horizontal spring (e.g. slinky spring) can be moved to and fro to generate waves which travel along the rope to the other end. This produces longitudinal waves.
- These are both mechanical waves.
Sound waves
- Air molecules vibrating are responsible for sound waves. These are a type of mechanical wave and are longitudinal in nature.
Water waves
- Water waves such as ocean waves or ripples on a pond are mechanical wave and can be considered to be transverse waves.
Seismic waves
- Earthquakes produce two main types of waves. Both are mechanical waves.
- Primary (P) waves are the fastest waves and these are longitudinal.
- Secondary (S) waves are transverse waves.
Waves in a ripple tank
A ripple tank is a convenient way to view water waves in the lab.
A vibration generator causes a dipper to be pushed up and down in the water creating a series of waves that propagate through the water away from the dipper.
Light shining through the water surface undergoes refraction creating a series of light and dark patterns on paper placed below the water tray.
These lines we see are referred to as wavefronts.
A straight bar used as a dipper will create plane waves in the ripple tank.
A point dipper will create circular waves in the ripple tank.
| Waves & Sound | Next >> |
| Links |
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| Wave on a String [interactive app] |