Sink or Float

Fun Friday Activity

Your activity today is about finding out what objects you collect will sink or float.

What you will need.

A bag to collect nature materials in.

A medium bowl.

Water.

Paper and a pencil.

Measuring cups or jug.

A tablespoon.

Table salt (1 tablespoon per cup of water).

It is surprising that something as big and heavy as a ship can float but a small penny will sink! How is this possible? The long wide base of the ship displaces more water than the penny. The more water an object displaces, the greater the pressure pushing it upwards to the surface. It is the upward pressure that helps objects float.

1. Grab your bag and head outside to explore and collect nature objects. Look for things like pieces of bark, seedpods, leaves, acorns, stones, pine cones and more.
2. Once back home, sort out your objects into two piles. One pile for objects that you think will sink and another pile for objects you think will float.
3. Fill a medium bowl with water.
4. Place each object in the bowl one at a time and test your hypothesis (educated guess) about whether your object will sink or float. Record your results on your paper.
5. Dump out the water and refill the bowl with warm water, mixing in table salt until dissolved. (1 tablespoon of salt for each cup of water).
6. Place each of your nature objects back into the water. Does this change any of your results? Record your second round of results on your paper.

Please share your results and any photos of you doing your activity with us. We are looking forward to seeing how you all get on.