HSC Physics Question Thread

[DrDusk]

Hello!
Would someone please be able to explain to me the common misconception, gravity is a force of attraction between 2 objects with mass. Including the General Theory of Relativity? and any advice about depth studies and how to get good marks?
Thanks

Your in high school right...? General relativity is 4th year uni physics and it requires a far far advanced understanding.....
General relativity states that gravity is actually the bending of space-time. It states that every object with mass bends and warps the space-time around it which causes other objects to sort of 'fall' towards it, so in a sense gravity is not a force.

I'm not 100% sure with how this depth study stuff works but if your gonna do a depth study, general relativity is something you want to stay faaar away from. Try special relativity, its 10x easier.

[david.wang28]

Hello,
I have two questions that I am confused on in the attachments below. Can anyone please help me out? Thanks

[Coolmate]

I'm not 100% sure with how this depth study stuff works but if your gonna do a depth study, general relativity is something you want to stay faaar away from. Try special relativity, its 10x easier.

Thanks DrDusk 

[mani.s_]

Physics depth Study Year 11 (Module 3)

Hi, I have a physics depth study starting next week. It seems we have to design an experiment on how variations in pitch and loudness of sound change the characteristics of the sound wave. I have a deep understanding of the theory aspect of this part but I have no idea how to make practical, testing this question. Our practical has to give us quantitative data that we can analyse and evaluate. Any help is appreciated, Thanks

[saloni.aphale]

Can someone please help me with the question attached below.

[DrDusk]

Can someone please help me with the question attached below.

Let's make sense of what is fundamentally happening with the photoelectric effect.







Now doubling the intensity will increase the number of Photons of light which means more photons can undergo the photoelectric effect, meaning more photoelectrons should be ejected. So instantly rules out A and C. Now the reason D is incorrect is because from our calculations above we can clearly see that the light does not have enough energy to eject photoelectrons from metal Y, because the energy of the light is less than the minimum energy required, whereas for X it is greater. So the number of photoelectrons emitted cannot physically increase for Y, as it wont ever emit electrons at that frequency and wavelength of light in the first place!. So its B

[saloni.aphale]

Let's make sense of what is fundamentally happening with the photoelectric effect.







Now doubling the intensity will increase the number of Photons of light which means more photons can undergo the photoelectric effect, meaning more photoelectrons should be ejected. So instantly rules out A and C. Now the reason D is incorrect is because from our calculations above we can clearly see that the light does not have enough energy to eject photoelectrons from metal Y, because the energy of the light is less than the minimum energy required, whereas for X it is greater. So the number of photoelectrons emitted cannot physically increase for Y, as it wont ever emit electrons at that frequency and wavelength of light in the first place!. So its B

Thank you so much, that helped a lot !!!

[mani.s_]

Hi, I have a physics depth study starting next week. It seems we have to design an experiment on how variations in pitch and loudness of sound change the characteristics of the sound wave. I have a deep understanding of the theory aspect of this part but I have no idea how to make practical, testing this question. Our practical has to give us quantitative data that we can analyze and evaluate. Any help is appreciated, I have also attached my physics depth study notification below. Thanks!!!

[DrDusk]

Hi, I have a physics depth study starting next week. It seems we have to design an experiment on how variations in pitch and loudness of sound change the characteristics of the sound wave. I have a deep understanding of the theory aspect of this part but I have no idea how to make practical, testing this question. Our practical has to give us quantitative data that we can analyze and evaluate. Any help is appreciated, I have also attached my physics depth study notification below. Thanks!!!

I don't suppose your school has logger software that allows you to map the sound wave on a computer?? This is what we used in uni and it's a great way to get accurate data.

[Aryan.S]

Could some please provide me with an explanation for which type of radiation is the least suitable for medical procedures?

Any help would be greatly appreciated!

[DrDusk]

Could some please provide me with an explanation for which type of radiation is the least suitable for medical procedures?

Any help would be greatly appreciated!

Gamma radiation would obviously be the worst because it would go right through your body! Alpha and Beta radiation are much more highly ionizing but they are easily stopped by your skin and body, so its penetrating power is very low, meaning the damage done would be much less.

Basically safer radiation would be that which has lower penetration power

[blyatman]

Your in high school right...? General relativity is PHD level uni physics and it requires a far far advanced understanding.....
General relativity states that gravity is actually the bending of space-time. It states that every object with mass bends and warps the space-time around it which causes other objects to sort of 'fall' towards it, so in a sense gravity is not a force.

I'm not 100% sure with how this depth study stuff works but if your gonna do a depth study, general relativity is something you want to stay faaar away from. Try special relativity, its 10x easier.

GR is actually an honours-level physics course, and it doesn't require doing a PhD to understand it.

Might be worth talking about the very basic tenets of GR from a qualitative aspect, since SR has nothing to with gravity.

[DrDusk]

GR is actually an honours-level physics course, and it doesn't require doing a PhD to understand it.

Might be worth talking about the very basic tenets of GR from a qualitative aspect, since SR has nothing to with gravity.

Ah I see. This is what I thought initially but I was unable to find the course in my degree outline which is weird..

[blyatman]

Ah I see. This is what I thought initially but I was unable to find the course in my degree outline which is weird..

Yeh pretty sure it should be offered. I know it was offered at Usyd. Either way, can just learn it yourself by grabbing a textbook (recommend Gravity by James Hartle). Did 3yrs of research (undergrad and postgrad thesis) and published papers in GR but never took any courses in it lol, just learnt it by reading the textbook along with guidance from my supervisor.

Defs a fun topic to learn, and would've stayed in the field if there were jobs in it.

[Coolmate]

Hey Everyone,

I am in Year 11 and am going to do my Physics prelim exams soon. I was wondering whether anyone has any good tips and what the most important things I should study that I can use for the exam, to achieve a high mark?

Also, does anyone have any past prelim papers for Physics?... (The new syllabus is making it hard to find them).

Thanks in advance,
Coolmate