Air Pressure Curriculum

Section 3—Lesson 6: Applying Relational Causality to Reasoning About Boyle's Law

Understanding Goals

This lesson focuses on Boyle's Law. Students apply a relational causal model in which they focus on how air pressure and volume within a closed system are related. They also apply Boyle's Law to situations beyond closed systems.

Subject Matter

• Although the relationship between force and surface area defines air pressure, both volume and temperature affect air pressure.
• Boyle's Law states that at a constant temperature, the pressure times the volume of an enclosed gas remains constant. When one increases, the other decreases to maintain equilibrium.
• An increase or decrease in volume (and the resulting decrease or increase in pressure) is often the result of an air pressure differential between the inside and the outside of an object.

Causality

• A relational causal model can be used to understand Boyle's Law.
• When our current models do not explain our observations of a phenomenon, we need to re-evaluate either our model or our observations. Often, we need to discard our current model for a model with a better explanatory fit.