Shape and Strength

• Stand up egg using clay to hold it in place

• Place two piles of coins on the other end of the tray. Same height as the egg. You should have a triangle

• Wrap books in plastic cover. Place one book at a time.

• How many books can you place before the egg breaks?

Why it Works?

The shape of the egg makes it both hollow and light. It has an arch at each end, a good structure for supporting weight. The egg has a lot of strength lengthwise because the tall arches spread more weight. It is much easier to break when on its sides because these arches are weaker

Iceberg Ahoy!

• Pour hot water into jars

• Place one colored cube on the surface of the hot water

Why it Works?

As the ice melts to water its density increases. This makes it sink to the bottom of the container

Dive Deep

• Fill bottle with water almost to the top

• Cut both ends of a flexible straw to make a “U” shape

• Unbend a clip and make it into a c shape with both ends curling inwards

• Loop thin strips of clay around paper clip

• Put the jellyfish in the bottle

Why it Works?

When you squeeze the bottle, water is pushed into the straw compressing the air. Water weighs more than air so the jellyfish gets heavier and sinks.

Floating Eggs

• Fill two jars: one with cold and one with hot water

• Add one tablespoon of salt to the hot water. See if the egg floats

• If not, fish egg out and add salt until it does

Why it Works?

Salt dissolved in water increases the density of water. Dendser liquids are better at keeping objects afloat. This is why many things that will sink in fresh water, float in salted water.