2.3.35 - Longitudinal waves

Be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules.

Use - longitudinal waves to connect the rule to the data and decision in the question.

This matters because - longitudinal waves determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - longitudinal waves to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Longitudinal waves is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.