Science

Boats and Buoyancy

Sinkers or Floater- What makes something sink or float?

We tested a variety of objects to see if they would sink or float in water. The students learned many things are important in determining what an object might do:

• material it is made out of (metal, wood, plastic)

• size (big, little)

• weight (heavy or light)

• air

• shape

Ask your child what they object did when in the water:

penny, chalk, dishcloth, paperclip, crayon, feather, cork, rock, marker, string

Follow up with why do you think it floated or sunk?

At Home Challenge?

Pick a sinker or a floater object. Then try and make it float. Have your child explain what they had to do to make it float or sink (did they change the shape, add something buoyant to it, add air to it etc...).

Stability

What does it mean to be stable?

What makes a boat stable? shape is important, width, keel

What is a keel?

**A keels job is to help keep the boat STABLE. Prevent it from tipping over.

Why is it important that a boat is stable?

Try this at home:

*with an adult is recommended** Check out the 2nd video on the right for video instructions.

You will need:

• 1-3 corks

• Nails 4-6

• Toothpick

• -sail (foam, paper)

• Tinfoil

How does the keel help the boat?

Why does adding more corks help make your cork boat more stable?