1. The truth that fish can sink and float.
There is a vial-like thing in the body of the fish called the "swim swim bladder" biào. When there is less air in the maw, the fish can swim in the water; when there is more air inside, the fish can swim on the surface of the water. Control the amount of air to hover in the water.
air bladder
Comparing F float and G, it is found that the gravity of the fish itself cannot change quickly, and because of the characteristics of the fish maw retracting the airbag, so the fish is changed by changing its own volume, changing the ∨ row, from changing the buoyancy size, when F floats > G, sinks, when F float = G, levitates; when F floats < G, sinks.
2. Secrets of submarines
Inspired by the structure of fish bodies, submarines were designed and built. Submarines have a ballast cabin inside. When the submarine floats on the surface, the ballast tank is filled with air and the valves are closed.
When sinking, the valve opens and seawater enters the ballast tank.
When floating, air is fed into the ballast compartment with a pump, and the seawater in the cabin is removed.
Because the submarine extension can not change the characteristics of its own volume, so it is by changing its own buoyancy, can only change its own gravity to achieve floating and sinking, when F floating > G, sinking, when F float = G, levitation; when F floating < G, sinking.
Video loading...