Float or Sink?
WHAT YOU NEED:
- A big bowl, a bathtub or a sink filled
- Modeling clay or plasticine
WHAT TO DO:
1. Roll your modeling clay into a ball and
drop it into the water – does it float or sink?
2. Now, pull it back out and and press the
modeling clay into a thin sheet – then mould it into a boat shape.Make the sides as high as possible so no
water can get in.
3. Place your boat into the water – does it
float now?If it still sinks, try
modeling it a little bit more until it’s the right shape.Once it’s the right shape it will float on
the surface of the water.
4. When you have your modeling clay boat
floating, try putting marbles in the boat to see how much extra weight it can
The Extreme Science behind this:
It’s pretty interesting that the same piece
of modeling clay can both float, and sink, depending on its shape!
This all comes down to its density. Density is the amount of matter, or ‘stuff’
that is packed into an area.When the
plasticine is rolled into a ball, all of it’s matter is packed into a very
small area which makes it very dense.It’s density is higher than the density of the water, so it sinks.
When you re-mould the plasticine into a
boat shape, you’re changing it’s density by spreading the matter out over a
larger area, so that the water can support it!