Question

Why does submarine sinks and and float on water​

Answer 1

A submarine uses a specific type of tank called a ballast tank which makes it float and sink on water.

Step-by-step explanation:

The ballast tank compresses the air around it and when released increases density making it sink.

When the tanks are empty, the submarine's mass is decreased making it float to the top.

Answer 2

It has an aperture similar to the air bladder of a fish which when adjusted leads to floating or sinking