Fifth Grade
Worksheets
How Do Submarines Work?
A submarine is a kind of boat that can go under the water. It is shaped like a cylinder (think soda can) with rounded ends. This shape helps it glide easily and quickly under the water. There's a tall tower in the middle. Sometimes it is called the conning tower or the sail. It carries the navigational equipment. A submarine has small fins at the side near the back. They are called hydroplanes. The fins can be turned at different angles. This aims the flow of water and helps the sub turn in the water.
To dive under the water, a sub must have more density than the water. It does this by taking on more water. It has ballast tanks to hold ocean water or air. A sub dives by filling its ballast tanks with water. Filling the tanks with water makes the sub heavier. It can then submerge into the water.
When the sub wants to surface, air is blown into the ballast tanks. This forces the water out into the ocean. Filling the tanks with air makes the sub lighter. The sub now has less density than the water. It can float to the surface.
