ScienceFreePrintable

Plastilina Buoyancy Investigation

A free science worksheet ready for your classroom. Open in Kuraplan to grab the print-ready PDF, customize it for your students, or generate a fresh version in seconds.

Download now

Name:Date:

Plastilina Buoyancy Investigation

Harrison, Tui and Isla are testing tiny boats for a model harbour beside a city bus route. Use one piece of plastilina and a tub of water. Keep the plastilina the same for each test, change its shape, and record what happens. Ask an adult to help with the water.

Plan and predict

Think like a scientist: make a prediction before testing, then compare it with what you observe.

1.Which is the fairest test of two plastilina shapes?

Use the same amount of plastilina and the same water tub, but change the shape.
Use a large lump for one shape and a tiny lump for the other.
Use different tubs and different amounts of water.

2.Before you test, predict: will a ball of plastilina float or sink in water? Explain what you think will happen.

3.What does buoyancy mean in this investigation?

A push from the water that can help an object float.
The water changing into plastilina.
The object disappearing in the water.

4.Test the ball, then reshape the same plastilina into a shallow boat. Record what happened to each shape in the water.

5.When an object goes into water, what usually happens to the water around it?

The object pushes some water aside; this is called displacement.
The water disappears.
The water turns into air.

6.Draw your best floating plastilina shape. Add a waterline and label one feature that may help it float.

7.Why might the same plastilina sink as a ball but float when shaped like a boat? Use the words shape and water in your explanation.

Load the model boat

Use small counters as pretend cargo. Add them one at a time and keep the boat in the same tub.

8.Predict what may happen as you add counters to a floating plastilina boat.

It may sit lower in the water and eventually sink if too much cargo is added.
It will float higher with every counter.
The counters will make the water disappear.

9.Carry out the cargo test. How many counters did your boat carry before it began to sink or take in water? If it stayed afloat, write that it stayed afloat for your test.

10.Complete the investigation conclusion: My boat floated best when it was shaped like . I think this worked because .