# Fun Science Projects for Kids

## Hollow Strength

Your bones have hollow strength -- they're strong, even though they're hollow.

Did you know that many of the long bones in your body are hollow? You might say they have "hollow strength," because even though they're hollow inside (or filled with soft tissue), they're still able to support the weight of your body.

Being hollow means that they're lightweight, so it takes less energy to move them. (Imagine trying to walk or run if you had bones that were solid all the way through. It'd be like moving your legs with weights attached.) Having a hollow center gives them a better design and makes them stronger.

Confused? Give the following project a try, and you'll see what is meant by "hollow strength."

### What You'll Need:

• Notebook paper
• Tape
• Paper plate
• Measuring cup
• Wooden blocks or other weights

Step 1: Roll up a sheet of notebook paper into a tube about 1 inch wide. Tape the tube closed so it doesn't unroll. Repeat twice more so you have three paper "bones."

Step 2: Stand the bones up on their ends. Put a paper plate on top of the three rolls. The hollow rolls will support the plate.

Step 3: Now start adding wooden blocks to the plate. Count how many blocks the plate can hold before it collapses the bones. These bones are strong, so they might be able to hold quite a few blocks.

Step 4: Roll three more sheets of paper as tightly as you can, so there are no hollow sections. These bones use the same amount of paper, but they are much thinner. Stand them on end, and put the plate on top of them. Put blocks on the plate until these bones collapse.

Bones have amazing properties, but so does gunk. Keep reading fun science projects for kids to find out about one more project that defies logic.