S2.5.8 For the adult
Shape and floating
How can a ship made of steel float?
What this chapter teaches
The same clay sinks as a lump and floats as a boat. A hollow shape pushes aside more water, so the water pushes up harder. A steel ship floats because it is hollow and full of air, so the water it pushes aside weighs as much as the whole ship.
Three questions to ask
There is no one right wording. Listen for the idea.
- How can you make a lump of clay float?
- Why does a steel ship float when a steel nail sinks?
- Why can a boat with higher sides carry more?
After the chapter, the learner can
- Make a lump of clay float by shaping it into a boat
- Explain why a big steel ship floats
What they copy into their notebook
A hollow shape pushes aside more water. The water pushes up harder. That is why a clay boat floats and a lump sinks. A steel ship is hollow. It pushes aside a lot of water, so it floats.