Just quickly, can anyone actually confirm what they got for the efficiency question? I seem to recall hearing various answers from people after the exam but not once did I hear what I was hoping for.
Also, if anyone is curious as to what the grade boundaries have been for the papers since June 2009, I'll be attaching a document that was rather nicely posted a bit eariler on this thread. Sorry creator of the Excel document, I hope I haven't violated any copyright laws!
Having them in a table just seems so much easier than using AQA's website to look for each year individually.. Ugh!
I got this maybe take the good bits from mine if there are any and add to yours? Also what do you think I would get /70 I'd greatly appreciate it if someone gave me their scores
2a)0.55 2b) 240 2c) the horizontal displacement =ut. It takes the same time to falls and u is less and therefore the distance travelled is less TOO VAGUE
3a) Inital quick acceleration shown by steep gradient As it falls a drag force is produced As the object falls the drag force on it increases reducing the resultant force F=ma with respect to Newton's second law and so the acceleration decreases as it falls as shown by the gradient getting smaller Eventually drag is equal and opposite to weight Ball travels at constant Velocity shown by the straight part of the graph near the end of time Reference to Newton's first law as it moves at a constant velocity as there is no resultant force Some of the energy of the object is converted into internal energy of the oil It finally hits the bottom as shown by the vertical line at the end
3b) I did a striaght line to about 3/4 the way up the line before it hit the fluid Copied the graph from the page before for the second bit but starter it lower to show it's speed falls when it hits the oil Striaght line at the end
4a) I got the wrong as I said f *proportional sign* KL and defined the terms NO MARKS HERE 4b) 1200 n/m 4c) 9.4? I got this wrong I think I found how many squares there were and times by the area per square SHOULD HAVE BEEN 1.05 4d) the object is permanently stretched and doesn't return to its inital length 4e) striaght line to the x axis but a bit to the right than the first list as there is extension at the end of unloading 4d) more work required when loading
5a) n1>n2 Angle of incidence>critical angle
5b) 51 5c) 30 5d) it totally internally reflects as angle of incidence is more than critical angle DOES NOT REFLECT 5e) reflects away at same angle GOES AWAY FROM THE NORMAL
6a) 90 out of phase 270 out of phase
6b) up, down to equilibrium, down again, back up to equilibrium MENTION 1/4 OF A CYCLE... TOO VAGUE 6c) it's transverse as longitudinal can't be polarised THIS ONLY GETS 1 MARK 6d)1.7 x10 to the 8 6e) 750 6f) was there any more questions here?
7a) light consists of a single wavelength 7b) lower intensity, wider fringes 7c) don't shine it into people's face or look along the beam as it will damage the eye 7d) central white maximum, subsidiary maxima consisting of spectra with blue on inside and red on outside of the fringes. The intensity is less than laser light.
I think I got 54/70 maybe. As I've taken time to create this could you give me yor opinions on my score?
Didn't want to be too harsh so not correcting all your mistakes
I think everyone misunderstood the last question on the paper. It was white light passing through a single slit. Look at the textbook page 202, figure 2. Apparently no one here realized it.
EDIT: It wasn't a easy question.
I think everyone realised? I haven't seen any respond to it as if it were a double slit question.
No obvious mistakes where I can see you've definitely dropped a mark (outside of the ones you've identified). A couple of words in there that they might penalise you for misuse or whatever. Most of the marks you'll drop will probably be if you haven't quite used the right terms or you've missed something silly. Hard to give an accurate estimate but I wouldn't think you'd be much lower than 52ish but I could be wrong. Physics and especially the written questions are ones where you can lose a fair few marks without realising it.
I think that had to prove that the angle was 30 degrees for that question, so that would be correct.
No this is the last part where we had to draw the path the ray, it reflected at 60 degrees and then refracted at a normal perpendicular to the previous normal. So the incidence was 90-60 = 30. 30< critical angle so refracts at 20.9 degrees to be specific (20.9 was not required).
I think everyone realised? I haven't seen any respond to it as if it were a double slit question.
No obvious mistakes where I can see you've definitely dropped a mark (outside of the ones you've identified). A couple of words in there that they might penalise you for misuse or whatever. Most of the marks you'll drop will probably be if you haven't quite used the right terms or you've missed something silly. Hard to give an accurate estimate but I wouldn't think you'd be much lower than 52ish but I could be wrong. Physics and especially the written questions are ones where you can lose a fair few marks without realising it.
No this is the last part where we had to draw the path the ray, it reflected at 60 degrees and then refracted at a normal perpendicular to the previous normal. So the incidence was 90-60 = 30. 30< critical angle so refracts at 20.9 degrees to be specific (20.9 was not required).
Don't think you had to write the angles on - it was only one mark.
Didn't want to be too harsh so not correcting all your mistakes
It does totally internally reflect. You work out that the critical angle is 51 and you are giving the angle 30+22 as the approximate angle of incidence... hence TIR. For the question about the polarised waves. the deduction made can only be that the waves are transverse, this is because longitudinal waves cannot be polarised. Please if you do insist on marking others make sure that you know what the answers were.
It does totally internally reflect. You work out that the critical angle is 51 and you are giving the angle 30+22 as the approximate angle of incidence... hence TIR. For the question about the polarised waves. the deduction made can only be that the waves are transverse, this is because longitudinal waves cannot be polarised. Please if you do insist on marking others make sure that you know what the answers were.