Search results
Results from the WOW.Com Content Network
Oxygenated water is taken into the mantle cavity to the gills and through muscular contraction of this cavity, the spent water is expelled through the hyponome, created by a fold in the mantle. Motion of the cephalopods is usually backward as water is forced out anteriorly through the hyponome, but direction can be controlled somewhat by ...
Ships float in the water at a level where mass of the displaced water equals the mass of the vessel, so that the downwards force of gravity equals the upward force of buoyancy. As a vessel is lowered into the water its weight remains constant but the corresponding weight of water displaced by its hull increases.
The vertical/Z axis, or yaw axis, is an imaginary line running vertically through the ship and through its centre of mass. A yaw motion is a side-to side movement of the bow and stern of the ship. The transverse/Y axis, lateral axis, or pitch axis is an imaginary line running horizontally across the ship and through the centre of mass. A pitch ...
Flying fish are not true fliers in the sense that they do not execute powered flight. Instead, these species glide directly over the surface of the ocean water without ever flapping their "wings." Flying fish have evolved abnormally large pectoral fins that act as airfoils and provide lift when the fish launches itself out of the water.
In other words, for an object floating on a liquid surface (like a boat) or floating submerged in a fluid (like a submarine in water or dirigible in air) the weight of the displaced liquid equals the weight of the object. Thus, only in the special case of floating does the buoyant force acting on an object equal the objects weight.
A lateral line system allows it to detect vibrations and pressure changes in water, helping the fish to respond appropriately to external events. [3] Well developed fins are used for maintaining balance, braking and changing direction. The pectoral fins act as pivots around which the fish can turn rapidly and steer itself.
A raised framework or hood like covering over a small hatchway on a ship. boom 1. A floating barrier to control navigation into and out of rivers and harbors. 2. A spar attached to the foot of a fore-and-aft sail. [19] 3. A spar to extend the foot of gaffsail, trysail or jib. [19] 3.
When they encounter a shoal of senorita fish, they stop and form a tight ball and hang upside down (pictured), each fish waiting its turn to be cleaned. The senorita fish pick dead tissues and external parasites, like parasitic copecods and isocods, from the skin of other fishes. [citation needed] Some shoals engage in mobbing behaviour.