HSC Physics Predictions / Thoughts (1 Viewer)

Speed’o’sound Sonic

Well-Known Member
I'd imagine if this came in exam many marks would be lost for not justifying why it is one of the most important equations I.e comparing significance to Newton and Maxwell's equations e.g
No doubt, true that. That's why I wouldn't expect to see it in a final, it just seems a bit open-ended, a bit loose and potentially difficult to mark. However, it's still likely it could come up and for anyone reading - just take a minute to plan out the points you'll discuss, and read the directive (e.g. assess, explain) make sure to address it. 3 hours is a long time and you don't want to rush it and get a 7 or 8/9 just to end up with 20 minutes spare time at the end.

ktbffh11

Member
can someone help me with this?
r= 25.6m and m=885kg
the kinetic friction between tyres and road is 9420N

the velocity you calculate in part a) is 16.5m/s on a non-banked road. thing is I keep getting a lower velocity for the banked road.

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Speed’o’sound Sonic

Well-Known Member
can someone help me with this?
r= 25.6m and m=885kg
the kinetic friction between tyres and road is 9420N

the velocity you calculate in part a) is 16.5m/s on a non-banked road. thing is I keep getting a lower velocity for the banked road.
Not sure how many marks are allocated. Either you take the short method and let v = (rgtan(angle))^(1/2) or you take the 'long way' and let the horizontal component of friction be equal to the centripetal force, and vertical mg, and work out that way to prove that result. The value of m shouldn't matter as it is a common factor and will 'cancel out' when dividing simultaneously.

ktbffh11

Member
Not sure how many marks are allocated. Either you take the short method and let v = (rgtan(angle))^(1/2) or you take the 'long way' and let the horizontal component of friction be equal to the centripetal force, and vertical mg, and work out that way to prove that result. The value of m shouldn't matter as it is a common factor and will 'cancel out' when dividing simultaneously.
when you use that formula you get a value for v less than 16.5 m/s

Speed’o’sound Sonic

Well-Known Member
when you use that formula you get a value for v less than 16.5 m/s
Well, I'll be honest. I have no clue on that one ahah. I'd look back at your answer for part 1, re check values given for radius and angle of inclination - and maybe even gravitational acceleration) and if that fails the question is broken I guess

ktbffh11

Member
Well, I'll be honest. I have no clue on that one ahah. I'd look back at your answer for part 1, re check values given for radius and angle of inclination - and maybe even gravitational acceleration) and if that fails the question is broken I guess
This is the solution (it’s the 2019 CSSA paper) but they’ve literally done pythagoras wrong so I feel like the questions just not right

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Speed’o’sound Sonic

Well-Known Member
This is the solution (it’s the 2019 CSSA paper) but they’ve literally done pythagoras wrong so I feel like the questions just not right
Yeah I’d be using trig simultaneously rather than pythagoras. All good, results are often wrong as this is just one example

Fabrizio

Active Member
How can you relativistic momentum or Dr Broglie matter waves to E=mc^2?

Also, those questions are bad. More marks can be deducted than expected because of some small element missing I.e you can get 7/9 even though everything seems to be there, that doesn't happen with calculation/derivation
de Broglie's equation is derived from combining Einsteins mass energy equivalence and planks E-hf

Speed’o’sound Sonic

Well-Known Member
de Broglie's equation is derived from combining Einsteins mass energy equivalence and planks E-hf
Where'd you get that from?

Fabrizio

Active Member
Where'd you get that from?
Cant remember which textbook but its a thing you can just search up

Speed’o’sound Sonic

Well-Known Member
Cant remember which textbook but its a thing you can just search up
Cheers, I straight up didn't know that haha. That concept would further tie into our understanding of matter then I guess.

Fabrizio

Active Member
Cheers, I straight up didn't know that haha. That concept would further tie into our understanding of matter then I guess.
Its one of my main links along with it also satisfying the condition for quantised angular momentum in Bohrs orbit

homeworkatedog

Member
Only good for basic scientific skills haha. I think it's likely there'll be a graphing question, only thing I don't want to see is an 'error bar' question
error bar??

Greninja340

Active Member
Guys is mod 8 for physics hard, if not what mod did you guys find the hardest

Vxncent288

New Member
Is the CNO cycle present in red giants as well as hotter main sequence stars? If asked to identify the dominant nuclear reaction in red giants, do we go with CNO cycle or the triple alpha process?

shashysha

Well-Known Member
Is the CNO cycle present in red giants as well as hotter main sequence stars? If asked to identify the dominant nuclear reaction in red giants, do we go with CNO cycle or the triple alpha process?
CNO cycle is in stars >1.3 solar masses in the main sequence. For red giants, since its out of the main sequence, the nuclear reaction would be the triple alpha process fusing He > C if i remember right

shashysha

Well-Known Member
Guys is mod 8 for physics hard, if not what mod did you guys find the hardest
the whole module is memorisation and understanding and its long asf

Esdog07

New Member
Since u lot are all pretty smart, anyone know how to solve Schrodinger's differential equation?

Fabrizio

Active Member
Im relying on the extended responses being on models of atoms or the light ones, know barely anything for the points like how radiation turned to matter
Guys is mod 8 for physics hard, if not what mod did you guys find the hardest
honestly probably mod 6.