Bi-Metallic Strip
| Physics, Chemistry: | Properties of Metals, Young's Modulus |
| Grade Range: | Elementary School, Middle School, High School |
| Format: | Hands-on, Stage |
WRITEUP UNDER CONSTRUCTION
Materials
- Bi-metallic Strip
- Blowtorch or similar
- Dry Ice or similar
Safety Precautions
Please read the Fire Safety and Cryogen Safety sections of the Demonstration Safety page before performing this demonstration.
This demonstration requires: thermal gloves, goggles.
Demonstration
- Show the Bi-Metallic Strip to the audience, and point out the two metals on it (Bronze and Nickel).
- Use the Dry Ice or similar Cryogen to cool the strip. It will start to bend over! The more you cool it, the more extreme the bend will get.
- Let the strip warm up for a minute or so. During this time, ask the audience to identify which side it bent towards. What can they deduce from this?
- Use the Blowtorch or similar heat source to warm the strip. It will now start bending, but in the opposite direction! The longer you heat it, the more it will bend.
- Compare earlier thoughts to this result. What do they think is happening?
Why This Works
Short Explanation
This is where you would provide a basic, easy-to-understand explanation of the demonstration. Try not to use too much "Science Jargon", and if needed add any explanation tips, like comparing the demo to something kids are familiar with.
Full Explanation
This is where you will explain the demonstration in full, and provide all additional information that pertains to the demo. Unlike the short explanation above, this should be worded so someone who is familiar with the topics might understand it. If needed, you can provide equations and citations for additional sources of information on the topic. This is also where you will find some answers for trickier questions, such as "How does a plane fly upside-down?" for the Bernoulli's Principle demo. If you want to add a floating box for equations, copy the following:
| This will give you | a floating box. |
| The box will be | centered for you. |
Additional Information
- Any extra tidbits that do not fit into other sections
- This demonstration is a part of the (insert Stage Show here)