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.
Landforms of erosion. Headlands and bays. Headlands and bays most commonly form along discordant coastlines. Discordant coastlines form where geology alternates between bands of hard and soft rock (see image below). As soft rock, such as glacial till, is more susceptible to erosion it erodes more rapidly than more resistant rock such as chalk. This results in the formation of headlands and bays. Bays and headlands along a discordant coastline.