3.3.1.1
A progressive wave transfers energy without transferring the medium
Progressive Waves — AQA A-Level Physics
Key Definition
Progressive wave — A wave that transfers energy from one point to another without transferring the medium itself.
- The medium (air, water, string) oscillates about a fixed equilibriumAn object is in equilibrium when the resultant force on it is zero. The object is either stationary or moving at constant velocityThe rate of change of displacement. A vector quantity. Measured in m s⁻¹.. position. Only energyThe capacity to do work. Measured in joules (J). moves along the wave.
- This distinguishes progressive waves from stationary waves, which store energyThe capacity to do work. Measured in joules (J). rather than transferring it.
- All progressive waves obey the wave equation: $v = f \lambda$.