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AQA Physics Unit 1 PHYA1 20th May 2013

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Guys, how do you design an experiment to show how light intensity affects the resistance of a LDR? :smile:
If a proton collided with another proton would the interaction be strong?


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How would you actually define a strange particle?, because the book says that a particle is strange if it contains a strange quark and decays by the weak interaction, but all hadrons decay by the weak interaction, so how does that differentiate it?

Would a particle be considered strange because it decays more slowly by the weak then expected for its larger mass? (so longer half-life), is this correct?
Original post by Jimmy20002012
If a proton collided with another proton would the interaction be strong?


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I think if it is just hadrons it is strong, just leptons its weak and leptons and hadrons its weak, but if a proton collided with another proton wouldn't they just transfer kinetic energy and be deflected?
Original post by JackAARfan9526
I think if it is just hadrons it is strong, just leptons its weak and leptons and hadrons its weak, but if a proton collided with another proton wouldn't they just transfer kinetic energy and be deflected?


So is it all we need to know is that hadrons is strong force if strangeness is conserved and leptons is weak force?


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I know all of the various rules when it comes to circuit calculations, but somehow when I look at the majority of the questions I just don't see how to apply them. Does anyone have any suggestions for acing the electricity section?!
I really need 110/120 ums minimum as my ISA is terrible and I need to uphold my A from PHYA2 :frown:

(Our teachers give us no help whatsoever when it comes to the ISAs, we're just thrown in - which, being an exam, is technically how it should be done - but they just don't appreciate how ridiculous the grade boundaries are due to the fact that every single school other than ours cheats in them........ :mad:)
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Goods
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Original post by jazzynutter
I know all of the various rules when it comes to circuit calculations, but somehow when I look at the majority of the questions I just don't see how to apply them. Does anyone have any suggestions for acing the electricity section?!
I really need 110/120 ums minimum as my ISA is terrible and I need to uphold my A from PHYA2 :frown:

(Our teachers give us no help whatsoever when it comes to the ISAs, we're just thrown in - which, being an exam, is technically how it should be done - but they just don't appreciate how ridiculous the grade boundaries are due to the fact that every single school other than ours cheats in them........ :mad:)


Try doing the EMPA...
Original post by Goods
Try doing the EMPA...


I don't suppose the grade boundaries for the EMPAs are any lower?
Original post by Jimmy20002012
So is it all we need to know is that hadrons is strong force if strangeness is conserved and leptons is weak force?


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Yes, but you also need to know that strangness is always conserved in the strong interaction but not the weak, so strangness is conserved in formation (strong) but not decay (weak). All strange particles are hadrons because they contain quarks, the only strange particle we need to know is the Kaon, which is a meson. Hadrons interact via the strong interaction but decay by the weak interaction, because the decay includes leptons, which are fundamental particles. Leptons interact via weak interaction but cannot decay. Also what is important is that the proton cannot decay it is the only stable baryon.
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Tuya
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Does anyone have a list of the possible 6 mark questions they can ask?
I can only this off the top of my head-
The water bath temperature control


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Original post by JackAARfan9526
How would you actually define a strange particle?, because the book says that a particle is strange if it contains a strange quark and decays by the weak interaction, but all hadrons decay by the weak interaction, so how does that differentiate it?

Would a particle be considered strange because it decays more slowly by the weak then expected for its larger mass? (so longer half-life), is this correct?


No they're called strange because they actually are strange and we don't know much about them compared to other quarks and particles :tongue:

The term strangeness was introduced because particles such as kaons would easily be produced during collisions & it seemed they would always appear... no one could explain it :smile:

Strangeness is conserved during the strong and electromagnetic interactions :smile: But not during the weak interactions. Just something you'll have to remember unfortunately :tongue:

Hope that helps :smile:
From the question in the attachment, when finding the frequency, I know that for 1.5 waveform it is 1.5 x 10= 15ms, to get one wave time period what do you have to do divide by 1.5 because of there being 1.5 cycles or by 1.5 as that is the time base?



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ImageUploadedByStudent Room1368654162.861659.jpg93.4KB
Original post by NabRoh
8 markers!? :shot:


I swear there are 8 markers...right?!

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Original post by Jimmy20002012
From the question in the attachment, when finding the frequency, I know that for 1.5 waveform it is 1.5 x 10= 15ms, to get one wave time period what do you have to do divide by 1.5 because of there being 1.5 cycles or by 1.5 as that is the time base?



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T=1/f

So f=1/T= 1/period in seconds

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Am I the only one who thinks the text book is absolutely awful? Not as bad for Unit 1 as unit 2, but still pretty bad!
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NabRoh
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Original post by x-Sophie-x
I swear there are 8 markers...right?!

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I checked there aren't. But there was a year where there were two 6 markers... yeah.

Original post by TheBeesKnees
Am I the only one who thinks the text book is absolutely awful? Not as bad for Unit 1 as unit 2, but still pretty bad!

They are indeed. Its almost silly that they have the "Exclusively endorsed by AQA" sign on them.
Original post by x-Sophie-x
T=1/f

So f=1/T= 1/period in seconds

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Yeah I understand that but we are shown 1.5 cycles, to find the period of one whole wave do we do the whole period shown by the number of cycles present, ie 1.5


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Original post by Jimmy20002012
Yeah I understand that but we are shown 1.5 cycles, to find the period of one whole wave do we do the whole period shown by the number of cycles present, ie 1.5


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Oh sorry, I misread the question.

You work out the timebase for ONE WAVE, so divide by 3 and multiply by 2.

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Original post by x-Sophie-x
Oh sorry, I misread the question.

You work out the timebase for ONE WAVE, so divide by 3 and multiply by 2.

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How does that get you your answer, because if you did that you would do 1.5/3 x 2= 1. What I did is find the total time period which is 1.5ms x 10 (squares) = 15ms then would you divide by 1.5 because there are 1.5 cycles or because the time base is 1.5?


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Original post by Jimmy20002012
How does that get you your answer, because if you did that you would do 1.5/3 x 2= 1. What I did is find the total time period which is 1.5ms x 10 (squares) = 15ms then would you divide by 1.5 because there are 1.5 cycles or because the time base is 1.5?


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Yep, dividing by 3 and multiplying by 2 is the same thing, surely?

15/3*2=10
15/1.5=10

Someone please correct me if I'm wrong.
(edited 10 years ago)

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