PIRA Class: 4A30.10

Purpose: 

Thermal expansion results from a change in the average separation distance between atoms as a material changes temperature. As the temperature of a material is increased, so does the amplitude of its atomic oscillations and average inter-atomic distances. Brass has a thermal expansion coefficient approximately twice as great as steel. Thus, brass will experience a greater expansion in its length than steel will for equal temperature changes. A bimetallic strip of steel and brass will thus bend toward the steel upon heating and toward the brass upon cooling.

Description:
Place the bimetallic strip in the fire until it bends noting which side it bent to. Then, place the strip into liquid nitrogen and wait for it to cool down and bend the other way.

Equipment:
Bimetallic strip, Bunsen burner or blow torch, matches, liquid nitrogen

Web Simulation:

https://physics.appstate.edu/catalog/4-thermodynamics/4a-thermal-properties-matter/bimetalic-strip 

Location:
Shelf 265 (matches), 247 (bimetallic strip), liquid nitrogen near sink