PSA4, PSA5, PSA6 Edexcel Salters Horners A2 Physics

Everyone else in my class found it easy... I thought it was way harder than any past papers

woo first to post legally!
i thought it was a reasonably nice synoptic paper!
however i messed up a few things,
i couldn't answer the first question - duh i know friends explained after! 3 marks gone
i didnt realise that the equation was in the form y = mx + c so i lost a mark there! so i also lost at least one mark on the find k question as i remembered last second and scribbled some stuff down!
im hoping i got a B!
someone else must be up its not early!

edit: also the last question there was 2 answers split between reasonably evenly between my class:

1) the photons would hit the wave gain some of its kinetic energy and by e = hf they would have increased frequency! - mine
2) the doppler effect as it hits the wave that is moving close it would rebound with a higher frequency! I dont understand how it could be this as if it was a regular waveform ( a sin wave or something) surely the times when it is moving closer and further away would even out so it would keep the same frequency????

please be the first! :s

There is no difference between those two answers except that 1 uses the photon model and 2 uses the wave model (you said e=hf, which is the whole point). The thing is however, the question was talking about red shift (visible light ==> THZ freq, or 10^17 => 10^12) so while your answer would have been correct, it isn't because of a very simple mistake. Unlucky...

Easily the hardest PSA6 ever i cannot believe the people who say its easy. Everyone in our class found it solid so maybe we weren't taught correctly, but I thought question 1 was the hardest and killed your confidence before starting the paper.