Hi, for the last question you did, do we need to write each equation separately and then figure out what conservation laws apply or is there a shorter method we can use to save the exam time. If possible, could you send its mark scheme
It does say ‘deduce’ so you have to show the examiner your deductive process. It doesn’t and didn’t take that long to do, in an exam, you would be faster as you’re not describing what you’re doing. Even so, it is a 6-mark question so you’re expected to take 6-8 minutes to do it. You could just label each equation given with a number and then go through each conservation law. But make sure it is clear to your examiner that you are not just guessing, that there is a deductive process involved in whether you decide it is possible or not.
hey, i'm having alot of issues in this bit of the specification. i just can't seem to answer questions which revolve around the quark composition of elements. it would be amazing if we can have a video detailing this topic and/or a video showing how to approach these questions. one of them, in WPH04/01 Oct 2018 question 11 has it, and i just cant seem to understand how to approach a question of a similar kind.
Okay, there are a couple of points that apply here. Baryons contain 3 quarks or 3 anti-quarks (no mixtures). There are only 6 types of quark: u, d, c, s, t, b (plus their anti-) That question says a 'hyperon' is a baryon so we know it has 3 and it says that at least 1 of them is s. But no c, b, or t. So you have to explain why there are 6 possibles. Excluding anti-quarks because it says '1 strange' which means they must be made of particles and no antiparticles. So we have 3 quarks we can use: u, d, s. Every possibility must have minimum 1 s. So our possibles have to be: sss, ssu, ssd, suu, sdd, sdu - there are no other combinations that follow those restrictions. The second part of the question is about the symmetry of the standard model. 3 classes of leptons and 2 classes of baryon already discovered by 1974, following a similar pattern, it seemed likely that there was a 3rd class of baryon with 2 forms (top and bottom). Does that help? Send me info on another if you'd like me to explain that. You'll see a pattern emerging. Once you get this, these are the BEST questions.
What I did is write out the quarks as a brief standard model: uct dsb Then I eliminate those that are 'not allowed', depending on the question of course. Leaving only a little bit of combining. It's a good idea to include the charges in your brief mental model. Top row are +2/3, bottom row -1/3. Then any question about composition or charge is just a matter of putting them together.
@@nutshellphy a little doubt. how do we know what particle is a baryon/lepton? assuming all baryons have a specific baryon number and all non-baryon particles have a different specific number? likewise for leptons, how do we know whether a certain particle will have a lepton number or 1 and not 0? is it some sort of calculation that is done mentally? secondly, for the quark composition of elements, how do we know what element is a baryon and what element is a meson and whether or not it will have an antiquark or not? lastly, i've seen topical past papers on questions revolving around "strong and weak nuclear forces" , any details on that?
This video is great as it covers certain stuff that the pmt detailed notes fail to cover whilst also providing extra context, thanks.
Glad it was helpful!
Nailed my paper today, thanks to you. What a legend!
Really? Delighted to hear it!! The work pays off when you get to have that feeling. Very well done.
@@nutshellphy yessir! just to confim, the syllabus for WPH15 is upto date and completed in the playlist right?
thank you sooo much, did physics watching vids from here, and damn what a dub paper.... thank you soo much bless you
You’re very welcome! So glad it went well.
Hi, for the last question you did, do we need to write each equation separately and then figure out what conservation laws apply or is there a shorter method we can use to save the exam time. If possible, could you send its mark scheme
It does say ‘deduce’ so you have to show the examiner your deductive process. It doesn’t and didn’t take that long to do, in an exam, you would be faster as you’re not describing what you’re doing. Even so, it is a 6-mark question so you’re expected to take 6-8 minutes to do it.
You could just label each equation given with a number and then go through each conservation law. But make sure it is clear to your examiner that you are not just guessing, that there is a deductive process involved in whether you decide it is possible or not.
isnt it the top quark not the bottom? bottom was discovered first no?
Yes… did I say it was the bottom? Yikes. Yes, it was the top that was discovered last. Slip of the tongue, sorry!
@@nutshellphy ya at 10:13 its ok thanks for clearing it up >
Thanks for spotting it and letting me know!! I’ll put something in the description about it. Daft because it’s in the spec point.
do we just need to know the up and down quark or the others too?
You need to know the names and fractional charges of the others so you can figure out structures of baryons.
hey, i'm having alot of issues in this bit of the specification. i just can't seem to answer questions which revolve around the quark composition of elements. it would be amazing if we can have a video detailing this topic and/or a video showing how to approach these questions. one of them, in WPH04/01 Oct 2018 question 11 has it, and i just cant seem to understand how to approach a question of a similar kind.
Okay, let me have a look at it and I’ll see what I can do…
Okay, there are a couple of points that apply here. Baryons contain 3 quarks or 3 anti-quarks (no mixtures). There are only 6 types of quark: u, d, c, s, t, b (plus their anti-)
That question says a 'hyperon' is a baryon so we know it has 3 and it says that at least 1 of them is s. But no c, b, or t. So you have to explain why there are 6 possibles. Excluding anti-quarks because it says '1 strange' which means they must be made of particles and no antiparticles.
So we have 3 quarks we can use: u, d, s. Every possibility must have minimum 1 s.
So our possibles have to be: sss, ssu, ssd, suu, sdd, sdu - there are no other combinations that follow those restrictions.
The second part of the question is about the symmetry of the standard model. 3 classes of leptons and 2 classes of baryon already discovered by 1974, following a similar pattern, it seemed likely that there was a 3rd class of baryon with 2 forms (top and bottom).
Does that help? Send me info on another if you'd like me to explain that. You'll see a pattern emerging. Once you get this, these are the BEST questions.
What I did is write out the quarks as a brief standard model:
uct
dsb
Then I eliminate those that are 'not allowed', depending on the question of course. Leaving only a little bit of combining. It's a good idea to include the charges in your brief mental model. Top row are +2/3, bottom row -1/3. Then any question about composition or charge is just a matter of putting them together.
@@nutshellphy thank you so much. this helps alot.
@@nutshellphy a little doubt. how do we know what particle is a baryon/lepton? assuming all baryons have a specific baryon number and all non-baryon particles have a different specific number? likewise for leptons, how do we know whether a certain particle will have a lepton number or 1 and not 0? is it some sort of calculation that is done mentally?
secondly, for the quark composition of elements, how do we know what element is a baryon and what element is a meson and whether or not it will have an antiquark or not?
lastly, i've seen topical past papers on questions revolving around "strong and weak nuclear forces" , any details on that?