The 4-mark resonance answer
● VERBATIM — examined word-for-word(1) System has natural frequency f₀. (2) Periodic driver transfers energy to it. (3) As f_d → f₀ the rate of energy transfer increases, so amplitude grows. (4) At f_d = f₀, energy transfer is at the maximum rate and amplitude is maximum — resonance. (+ damping lowers and broadens the peak.)
What this actually means
The model paragraph, four steps: the system has a natural frequency f₀; the periodic driver transfers energy to it; as f_d approaches f₀ the rate of energy transfer increases, so the amplitude grows; at f_d = f₀ the energy transfer is at its maximum rate and the amplitude is maximum. That is resonance.
Add the damping rider when the question shows curves: heavier damping lowers and broadens the peak.
Deploy it verbatim. It is a mark scheme wearing paragraph clothing.
Prove it — watch it be true
- Sweep f_d slowly from far below f₀
- Watch the amplitude climb as the match improves: step 3 happening live
- Park at f_d = f₀: maximum energy transfer, maximum amplitude — step 4