## Thermal Expansion

The purpose of our experiment was to determine the coefficients of linear expansion for aluminum, steel, and copper. To do so, we heated tubes of each type of metal with steam. We measured the resistance, from which we derived temperature, and the change in length. The expansion was measured in hundredths of a millimeter by a thermistor connected to the base. The resistance was measured by an ohmmeter, from which we converted to degrees Celsius. With these numbers and the original length we were able to calculate the coefficients of linear expansion using the formula A = "L / (L0 * "T). We performed two-sample t-tests between each of the types of metal: Copper vs. Aluminum, Copper vs. Steel, and Steel vs. Aluminum. We found that the Aluminum had the highest coefficient, and Steel had the lowest, meaning that Aluminum expanded the most, while Steel expanded the least.

### Research Done By:

Tim Bentley*Warren Mott High School*

Mike Niebrzydowski*Sterling Heights High School*