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.
Three landforms created by wind are; sand dunes, yardangs (half-teardrop shaped formations hill sized, and deflation hollows (wind swept depressions.
Coastal landforms created by erosion include headlands, bays and cliffs. Landforms created by deposition include spits, salt marshes and beaches.1  1. 2  2.andforms created by erosion. The coastline is constantly eroding. There are four key types of erosion: 1  Abrasion-waves transport material which hit the cliff and gradually wear it away. 2  Hydraulic action-as waves approach the coast they trap air and force it into gaps in the cliff.