Resources: Experiments - Why Don't Big Ships Sink?

Today, ships are made of steel and lots of heavy stuff. Some can weigh around 80, 000 tons. How can any of them possibly stay afloat? The reason is simple, and you can make your own ship float too.

All you need is:

• aluminum foil,
• a few paper clips,
• an empty aquarium (or similar large container)
• and water

Here's what you do:

1. Partially fill the aquarium or container with water.
2. Take the aluminum foil, bend it in half and make a boat. Does it float?
3. Add a few of the paper clips. Now, what happens?
4. Take another sheet of aluminum and tightly fold it in half, placing the same number of paper clips as in the first boat inside the flattened one. What happens?

Here's how it works:

The aluminum in the boat shape displaces more water than the flattened one. If the object has enough volume to displace an amount of water equal to its own weight, it will float. Its weight, or the force of gravity, will equal its buoyancy, or the force of the water pushing up on it.