AQA Physics PHYA4 - 20th June 2016 [Exam Discussion Thread]

What was the unit - I worked it out to be C^2 kg^(-2)?

I put -5Q, for the first one, was there a positive version?

I also put -4 for the second one.

I'm confused 😭😩 what question require you to work out energy for the capacitors? Cause I literally don't remember working out energy at all :s

which question was this?

Yeah i got that too

what was the question again? I said he would to times his value of g by 4 to get the correct answer, is this right?

It asked for the direction of the force on x which was indeed y to x

Thats what i put but like 5 people below this have said otherwise

Ergh I done my graph like this, anyone else done it like this -_-

I dunno what the actual answer was but I put A because there were only about 3 A's out of 25 otherwise

1st one

area under graph

it was a MCQ where they gave us a capacitor which had a min and max value

yes.. i got something like that but i didnt go all the way down to zero... i stopped just before zero.. we should get atleast a mark for the shape of curve

For anyone wondering how to do the question about rearranging to find Ealpha (sorry it's a mess)

E = KEnucleus + Ealpha

V = -mv/N --> V^2 = m^2 v^2 / N^2

v = -VN/m --> v^2 = V^2 N^2 / m^2

KEnucleus = 1/2 N V^2 = 1/2 N (m^2 v^2 / N^2) = 1/2 m^2 v^2 / N

Ealpha = 1/2 m v^2 --> v^2 = 2*Ealpha / mE = 1/2 m^2 v^2 / N + Ealpha

E = 1/2 m^2 (2*Ealpha / m) / N + Ealpha

E = m*Ealpha / N + Ealpha

E = Ealpha (m/N + 1)

Ealpha = E (1 / (m/N + 1))

Ealpha = (N / (m + N))*E


Also here's a poll http://www.thestudentroom.co.uk/showthread.php?t=4176490

For the limitation I put dampening due to air resistance? Also on the MC, for the pendulum which one would have the largest amplitude? Overall I found section B okay, but the MC tricky.