AQA physics UNIT 3 monday 30th jan 2012
Physics exam discussion - share revision tips in preparation for GCSE, A Level and other physics exams and discuss how they went afterwards.
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Re: AQA physics UNIT 3 monday 30th jan 2012I'm pretty sure it isn't, I'm afraid. Oh well!(Original post by mazam)
I wrote 15 as well though I'm not sure if its right.
Also how did you get the answer 3.14 for the magnification?
And 0.15m for the screw question, don't you have to divide it by two. As 0.15 is the distance there and back and you want the distance to the crack.
Magnification was image height / object height.
Yeah, probably did actually... I do far better on the more difficult A level papers than I do on these...
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Re: AQA physics UNIT 3 monday 30th jan 2012Yeah, so it was 6000 x 0.0000025 = Distance there and back. So dividing this by two would have been the right answer I suppose! Unless it wanted the total distance traveled by the wave?(Original post by CaptainJim)
Ok, so doing this made me go
and now I'm at a 
Very hard, hoping for grade boundaries to be as low as the *something thats low*
I got 3 for the magnification and the time base was 0.000005.
What were the Bode's Law questions on? I've forgotten
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Re: AQA physics UNIT 3 monday 30th jan 2012
I felt that the timebase question was unfair considering they added a key of:
1cm = 0.000005, while in actuality each square was 0.5cm (measured)
Because of which I times the timebase by 2.5CM rather than 5CM and got a the answer that way.
I was thinking about going the other way but then assumed they put that there to trick people up, looks like it was the opposite to what I was thinking.
Now tell me how that has anything to do with testing our scientific ability?
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Re: AQA physics UNIT 3 monday 30th jan 2012What were the two numbers you divided to get 3.14?(Original post by VY Rose)
I'm pretty sure it isn't, I'm afraid. Oh well!
Magnification was image height / object height.
Yeah, probably did actually... I do far better on the more difficult A level papers than I do on these...
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Re: AQA physics UNIT 3 monday 30th jan 2012(Original post by mazam)
And 0.15m for the screw question, don't you have to divide it by two. As 0.15 is the distance there and back and you want the distance to the crack.

















Yep, the grade boundaries better be low
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Re: AQA physics UNIT 3 monday 30th jan 2012
Bodes law I put yes because the calculations where similar to the actual distance, then the one about a planet in between mars and Jupiter at 2.8Au I said that the scientists opinion would change because the predicted distance was the same as the actual distance, the last one I didn't know i said the calculation may have been outdated and the orbits may have changed :/
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Re: AQA physics UNIT 3 monday 30th jan 2012I got 0.5714.............(Original post by MrLegendary)
hey guys, new here, what answer did you get for the magnification? something along the lines of 3.14 ??
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Re: AQA physics UNIT 3 monday 30th jan 2012I got 0.075 don't you have to divide it by 2 because it's there and back?(Original post by sandeater)
how did you get 0.15m for the front of the screw i spent ages trying to do it but i couldn't explain?>??? -
Re: AQA physics UNIT 3 monday 30th jan 2012Damn! I forgot about that.(Original post by luke)
I got 0.075 don't you have to divide it by 2 because it's there and back? -
Re: AQA physics UNIT 3 monday 30th jan 2012No dont think thats right sorry...Firstly it said you have to only draw 2 rays, and secondly, the green ray should go through the focus on the right side and im not sure what the yellow one was... then you have to trace the rays back and a virtual larger image is formed on the left(Original post by luke)
Did anyone get something like this for the ray question?

Everyone got 3.14 for the magnification apparently, am I the only one who got this and 4/7 = 0.57 for the magnification
you got one ray right so hopefully youll get at least one mark for that!
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Re: AQA physics UNIT 3 monday 30th jan 2012I think here you got confused between a lens and a mirror. You will probably get a mark for the middle ray, and another if you remembered to put the the arrows on the rays.(Original post by luke)
Did anyone get something like this for the ray question?

Everyone got 3.14 for the magnification apparently, am I the only one who got this and 4/7 = 0.57 for the magnification -
Re: AQA physics UNIT 3 monday 30th jan 2012Not forgetting that an image magnified by 0.57 would be smaller! :P(Original post by Zaii786)
No dont think thats right sorry...Firstly it said you have to only draw 2 rays, and secondly, the green ray should go through the focus on the right side and im not sure what the yellow one was... then you have to trace the rays back and a virtual larger image is formed on the left
you got one ray right so hopefully youll get at least one mark for that!
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Re: AQA physics UNIT 3 monday 30th jan 2012Very similar to what I put(Original post by Manunited_96)
Bodes law I put yes because the calculations where similar to the actual distance, then the one about a planet in between mars and Jupiter at 2.8Au I said that the scientists opinion would change because the predicted distance was the same as the actual distance, the last one I didn't know i said the calculation may have been outdated and the orbits may have changed :/
Going back to a previous point, I agree that they test stupidly. Why not just ask us for loads of memorable information, instead of trying to screw us over with odd question wording! :P -
Re: AQA physics UNIT 3 monday 30th jan 2012That's what I got...I'm surprised...everyone thought it was a hard exam but I didn't! The last question I found really easy aswell it's just total anticlockwise moment = total clockwise moment and you could work it out from there...! For the last one I got 375 N...(Original post by FiGuev)
pulse a was the crack and pulse b was the back of the screwLast edited by Big_Ben; 31-01-2012 at 19:22.

