Basically, a passive radiator is a reactionary device as the name suggests. When a driver (such as a subwoofer) is mounted to a sealed speaker box (enclosure), the physical forward/back movement of the speaker affects the internal air pressure of the enclosure.
The 3 landforms created by wave erosion sometimes called coastal  erosion are headlands and bays, cliffs and wave cut platforms and  finally caves, arches, stacks and stumps â¦ . Wave erosion is the  wearing away of land and the removal of beach by wave currents.
Erosional landforms such as river valleys and coastal cliffs are formed when forces such as wind and water wear away surfaces. Erosion often takes a significant amount of time, but its effects are easily measured by examining geological evidence such as rock layers.