How Do Submarines Work?

What does 'density' mean?

• How fast something moves

• How colorful something is

• How heavy something is for its size

• How loud something is

What helps a submarine go underwater?

• Big propellers

• Ballast tanks filling with water

• Special lights

• A giant magnet

Why do people use submarines?

• To fly in the sky.

• To drive on roads.

• To explore the ocean and find cool animals.

• To build houses.

How do submarines come back up to the top of the water?

• They use a big crane.

• They push air into their ballast tanks and water out.

• They turn on their lights.

• They wait for the ocean to push them up.