Nature of Waves
Waves transfer energy away from its source
Progressive (moving) waves carrier energy from one place to another without transferring any material.
- Electromagnetic waves cause things to heat up
- X-rays and gama rays knock electrons out of their orbits, causing ionisation
- Loud sound make things vibrate
- Wave power can be used to generate electricity
- Since waves carry energy away, the source of the wave loses energy
- Displacement, X, (in meters) - how far a point on a wave has moved from its undisturbed position
- Amplitude, a, (in meters) - maximum displacement
- Wavelength, λ, (in meters) - the length of one whole wave, from crest to crest or trough to trough.
- Period, T, (in seconds) - time taken for a whole vibration
- Frquenc, f, (in Hertz) - number of vibrations per second passing over a given point
- Phase difference (measured in degrees or radians) - amount of which one wave lags behind another.
Reflection and Refraction and Frequency
Reflection and Refraction
- Reflection - wave bounces back when it hits the boundary.
- Refraction - wave changes direction as it enters a different medium.
Frequency - inverse of the time period
Frequency = 1 / period
Units 1Hz = 1s-1