Key idea
Waves
v = fλ
Start with the central idea, then test it against a concrete element or example. A scientific model is useful when we know what it explains — and where its limits are.
Waves
The key idea
A wave is a propagating disturbance that can transfer energy and information without requiring a net transport of matter over the same distance.
Why it matters
Frequency, wavelength and propagation speed are linked; what oscillates locally depends on the kind of wave and its medium.
A picture to remember
Key idea
Waves
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Guided example
Waves
Start with the central idea, then test it against a concrete element or example. A scientific model is useful when we know what it explains — and where its limits are.
Put it into practice
Waves
Choose a concrete case linked to Waves. Write down the known information, what you are trying to find, and the units. Then state the rule, model or trend you will use. If a calculation is involved, keep the units visible at every line; if it is conceptual, state what changes and what remains fixed.
Check your answer
A strong answer contains four things: the starting situation, the variable that changes, the direction or numerical result, and one check. The check can be a unit, an order of magnitude, a limiting case or a comparison with a familiar example.