Experiment – Experimenting with Materials and Internal Forces

Experimenting with Materials and Internal Forces

How do different materials withstand internal forces? Try this experiment to find out.

What You Need

• Wooden craft stick

• Sponge

• Eraser

• Plastic straw

• New, unsharpened wooden pencil

What You Do

1. Read the rating scale at the bottom of this page.

2. Test how well each material withstands tension. Pull on each material from both ends. Use the rating scale for each material and record the results in the chart.

3. Test how well each material withstands compression. Push on each material from both ends. Use the rating scale for each material and record the results in the chart.

4. Test how well each material withstands torsion. Twist each end in a different direction. Use the rating scale for each material and record the results in the chart.

5. Test how well each material withstands bending. Press down on each end with your fingers. Press up in the middle with your thumbs. (Do not waste classroom materials! See if the pencil will bend without using enough force to break it.) Use the rating scale for each material and record the results in the chart.

Rating Scale
1	Weak: A very small amount of force makes the material change shape or break.
2	Fair: A small amount of force makes the material change shape or break.
3	Good: A lot of force makes the material change shape or break.
4	Very Strong: A lot of force makes no change or very little change in the material’s shape.

 

---

Now, show what you know!

Complete some questions about the experiment by clicking “Begin Questions” below.