Edexcel A Level Physics Paper 2: Advanced Physics II 9PH0 02 -10 Jun 2022 [Exam Chat]

Didn't think that the exam was too difficult, but I once again had trouble with time management, and I believe I must have left some 15 marks without anything written throughout the paper. If I hadn't stalled in 3 or 4 questions (noticed something wrong, had to re-do them), I think it would have been possible to finish the test on time.

Blasted through the multiple choice ones, only remember that the one that asked if the critical angle was larger or smaller than theta was A (or at least that was I put).
Can't remember the numbers so:
Question about string: I got 143 Newtons of tension; Young's Modulus decreases with increase in temperature, and it is proportional to the force on the string, so higher temperature decreases the tension, which decreases the speed of the wave which is proportional to the frequency, so high temp = lower frequency. Possibly I overcomplicated things here.

Question with the distant star: used the /\ LAMBDA / LAMBDA-ZERO = v / c, and I got a ridiculous speed, so I'm probably wrong. I think it was 3 x 10^7m/s. To get the /\ LAMBDA, we had to measure with the ruler the shift in the image above, finding the distance per nanometer, then found that the /\LAMBDA = 83.3 nanometers. The answer, I assumed, was "from the information, we can find out that the speed that the star is moving away from Earth is X".

Question with the flamingo: only did the last 3 parts, I think they were b), c) and d). For b), I wrote there was damping from the air so the oscilation stopped at some point; for c) I got what they suggested, 2.2 s or something for period I think. For d) I can't remember.

Question with the aluminum can: I got that the statement was wrong as the energy produced would only sustain the phone for 5.04 days, not 7.

Question about the Rubidium: only had time to quickly go through the 1st and last 2 parts. For a): same total of 87 I think, and one additional proton which I think meant 87-38 Strontium + 0--1 Beta- + v. For c), I wrote that the Rubidium half-life is so long, it is so rare that it is difficult to measure a statistically significant average. For d), I wrote that the half life being longer means the ages are further in the past.

Question about the decay: I got what the question stated in one of the parts (the part with them taking 10 days for activity to be the same). Can't remember exactly the number of atoms but I think it was something like 3 x 10^16.

Question about the lens: for the calculation, I got that the displacement had to be (0.453-0.432)cm or something like that. Don't remember the exact value of the standard distance of the lens from the sensor (here I set it as 0.453 cm). I know it was something very small, and I could tell they put "displacement" there knowing that people would put the total distance from the lens.

Does anyone expect your marks over 50?