Question 19M.3.HL.TZ1.a

ALTERNATIVE 1

«$Q=2\pi \frac{E_0}{E_0-E_1}»\Rightarrow E_1=\left(1-\frac{2\pi }{Q}\right)E_0$  ✔

$E_1«=\left(1-\frac{2\pi }{25}\right)\times 12»=9.0$«mJ»  ✔

reading off the graph, period is 0.48 «s» ✔

Allow correct use of any value of E₀, not only at the time = 0.

Allow answer from interval 0.42−0.55 s

ALTERNATIVE 2

use of $Q=2\pi f\frac{\text{energy stored}}{\text{power loss}}$ ✔

energy stored = 12 «mJ» AND power loss = 5.6 «mJ/s»✔

«f = 1.86 s so» period is 0.54 «s» ✔

Allow answer from interval 0.42−0.55 s.

Award [3] for bald correct answer.