The Physics PHYA2 thread! 5th June 2013

Was wondering, does anyone had the answers to the Examnation-style questions right at the back of the 'AQA Physics AS level' book by Nelson Thornes? P.210 I think. Thanks!

mmm, not what I was looking for, but thanks anyway

do you guys think we'd lose marks if we don't put our answers in SI units?

for example on question 4ci in the jan 2013 paper, I put 500,000N, but the mark scheme had the answer as 5*10^5, both are the same, but do you reckon I'd lose the answer mark?

hey wtf is up with question 4c iv) in jan 2013?

they rounded the answer wrong in the mark scheme

the answer is 1.65*10^4

but instead of rounding to 1.7*10^4, they rounded it instead to 1.6*10^4

I'm pretty sure you round up for numbers 5 and over....

Just what I was looking for myself, brilliant.... thanks !

oh thats alright then for SI units

btw for question 7e in jan 2013, do you guys know why the mark scheme put so much emphasis on 'even number of multiples of new wavelength'?

the only requirement for an in-phase relationship between two waves, is that theres a whole number of wavelength difference between them, it doesn't have to be an even number, right?

also, for 7c, I thought it was a minimum, I see the two waves are in phase, but the detector is at the point where the the two waves are both in equilibrium. If the detector was placed a bit to the left, then I get that it would be a maximum, but where its shown in the diagram, its a minimum surely

For 7c, I initially thought that a minimum would be generated as well, because, as you've said, they both reach their equilibrium point at the point they reach the dector (displacement of both waves = 0 at the detector).

However, upon looking at it closer, I realised that, actually, the wave on the left being received must travel a longer distance, than the wave on the right. So through actually counting the amount of peaks and troughs in both the waves being received, I saw that there were 6 whole wave periods on the wave on the left, and 5 whole wave periods on the wave on the right. Which meant that, considering path difference, if the path difference is a whole integer number of λ, a maximum would occur. Which, in this case, the path difference was 1λ, which meant a maximum would be detected.

For jan 13 7e, can you explain the answer? it's a bit confusing.

Was wondering, does anyone had the answers to the Examnation-style questions right at the back of the 'AQA Physics AS level' book by Nelson Thornes? P.210 I think. Thanks![/

https://college.esher.ac.uk/subjects/Physics/2012%20%202013/AS%202012-13/AUTUMN%20TERM%20UNIT%202/UNIT%202%20MARKSCHEMES%20FOR%20EXAM%20QS%20IN%20TEXTBOOK/Unit_2_End_of_unit_answes_to_examination_style_questions.pdf

Looks like I need a password for that link.

Was wondering, does anyone had the answers to the Examnation-style questions right at the back of the 'AQA Physics AS level' book by Nelson Thornes? P.210 I think. Thanks!

Is this what you're looking for?

do you guys think we'd lose marks if we don't put our answers in SI units?

for example on question 4ci in the jan 2013 paper, I put 500,000N, but the mark scheme had the answer as 5*10^5, both are the same, but do you reckon I'd lose the answer mark?