Bones are hard and strong, but did you know that some bones are not solid inside?
The hollow part is filled with something called marrow that looks like jelly and helps our body in many ways.
Now you might think that solid bones would be much stronger, but if bones were solid they would probably be too heavy for you to lift!
Try the experiment below to find out just how strong your hollow bones can be.
Experiment
1. Ask your teacher or an adult for an A4 sheet of paper.
- Examine it closely. Does it feel very strong?
- Could you tear or crumple it easily?
2. Now roll it into a tube and stick it with sellotape.
- How much weight do you think it would hold?
- You could try 0.5kg, 1kg or 1.5kg or a heavy book.
3. Test it out and see what happens.
Be careful not to drop the heavy items on your fingers or toes!
Analyse your results
When do you think the paper was stronger, when it was flat or when it was rolled into a cylinder?
Imagine how much stronger the paper cylinder would be if it was bone. Do you still think hollow bones aren't strong?
Find out about some other places where hollow tubes are used. Are they all places where a lot of strength is needed?