HSC Physics Question Thread

[Baylsskool]

I'm not too sure about that reaction, i think it would be safer to say that the neutron transfers some of its kinetic energy to the deuteriumin the collision.
The deuterium shouldn't absorb the neutron at all, as moderators are made from materials with light nuclei. If it did absorb the neutron then the most likely reaction would be a fission reaction and that is not the case.

Makes sense , thanks sam

[blasonduo]

Hello guys,

From the dotpoint: Identify data sources, gather, process, analyse information and use available evidence to assess the impact
of the invention of transistors on society with particular reference to their use in microchips and
microprocessors

How much of the uses in microchips and microprocessors would need to be known, since I only know of the impacts of transistors onto society

Hello! Describing what transistor are and how they benefit/disadvantage society IS most of it, as when you think about it, the impact as transistors on society was mainly due to the creations of microprossessors and microchips! To be sure, just name a technology that uses a microchip and a technology that uses a microprossessor (and what they do!!)

From that, you will be 100% sweet!!

Goodluck! You'll smash that exam!

[Mymy409]

Can somebody help me with Q9 of the 2015 paper?

http://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-physics.pdf

Thanks in advance.

[CyberScopes]

Can somebody help me with Q9 of the 2015 paper?

http://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-physics.pdf

Thanks in advance.

P and Q are fixed in place. Since P and R are in the same direction, the force between them pulls R to the left. But since Q and R are in opposite directions, the force between them pushed R to the right. So pretty much find both forces and add them:

Force : F ∝ I₁I₂L / d
Since I and L are constant; F = 1 / d

Now you're given the force between Q and R, thats F, so:
F = 1 / 10 to the right between Q and R

d is 20mm between P and R so force between P and R = 1 / 20 
Since F = 1/10 from before and youre tryna get an answer in terms of F, you can sub F as 1/10:

F between P and R = 1/10(2) = F/2

So F_QR to the right (positive) plus F_PR to the left (negative)
= F + - F/2 = F/2
Positive means to the right, so its B

(There is probably an easier way for this but this is what makes most sense to me )

[Baylsskool]

Can anyone explain why black bodies actually have peaks, i mean theoretically it would work if the curve was exponentially decreasing but that's not what Planck discovered, why is there a section of energy missing at the start, why does the body not emit large amounts of energy due to the lower wavelengths being given off?? Is there an explanation for this missing gap?

I mean with the ultraviolet catastrophe,why can't there be an infinite source of energy for an infinitly small wavelength, cause it checks out mathematically, we just havnt discovered any frequencies higher than gamma, of course it can't be infinite but surely there's more to discover so how can the peak wavelength be so?? Shouldn't it technically, if we did find the smallest wavelength possible at least hit the wall of the graph and decrease from there???


Mod Edit: Post merge

[Jayden Nguyen]

Hi there
Could someone please help me with this question: account for the properties of diffraction and interference by electrons.
ps: this site looks so cool!

[winstondarmawan]

Quanta to Quarks:
Would appreciate help with the question below:
https://scontent-syd2-1.xx.fbcdn.net/v/t34.0-12/22854697_1360395137419339_998506963_n.png?oh=0a008b316557edb40a47baa2393cc263&oe=59F2AF12
TIA!

[statues]

In the Quanta to Quarks Option:
Is it important to memorise the six types of leptons?
I've got the types of quarks down, and the fundamental forces I'm just not sure if it's important to memorise also the leptons - there's a lot to remember and I don't want to have information I won't need.
Many THanks

[sidzeman]

For Med Phys, B scans produce a 2D cross sectional image by moving the transducer around to view the body from different angles correct? But aren't sector scans a series of B scans that are taken at different angles? I'm not exactly sure what the difference is now could someone clarify please

[beau77bro]

help please... like i know the information but i dont know how to direct it to answering the question properly, could someone give me an example and explanation on how to approach this?

[CyberScopes]

For Med Phys, B scans produce a 2D cross sectional image by moving the transducer around to view the body from different angles correct? But aren't sector scans a series of B scans that are taken at different angles? I'm not exactly sure what the difference is now could someone clarify please

As far as I know, B scans themselves do not actually produce a 2D image, they only produce the set of "brightness dots" which shows the distance between organs. When there are multiple transducers producing B scans in a convex shape (as a sector scan), or if the transducer is moved like you said, then the 2D image is produced. B scans refers to more of how the different points of the organs are found (as compared to A scans), while sector scans is a way in which an image can be formed from these B scans. So you aren't wrong, but B scans and sector scans shouldnt be comparable cause they refer to different things (the type of scan verses how the scan is used to produce an image, if that makes sense).

[bsdfjnlkasn]

In the Quanta to Quarks Option:
Is it important to memorise the six types of leptons?
I've got the types of quarks down, and the fundamental forces I'm just not sure if it's important to memorise also the leptons - there's a lot to remember and I don't want to have information I won't need.
Many THanks

Hey there!

There's actually only 3 lepton names that you have to remember:
Electron, muon and tau

The other 3 are there antineutrinos so not too much to remember!

You should learn some extra information in case they ask you to compare leptons with quarks. I would say that leptons experience all four fundamental forces except the SNF (which quarks do experience) and that they are fundamental particles (aren’t formed of anything smaller than leptons).

Let me know if you need more help

[bsdfjnlkasn]

Hi there
Could someone please help me with this question: account for the properties of diffraction and interference by electrons.
ps: this site looks so cool!

Hey there, what topic is this for?

[bsdfjnlkasn]

Quanta to Quarks:
Would appreciate help with the question below:
https://scontent-syd2-1.xx.fbcdn.net/v/t34.0-12/22854697_1360395137419339_998506963_n.png?oh=0a008b316557edb40a47baa2393cc263&oe=59F2AF12
TIA!

Hey there,

They would experience an attractive force - not sure what the second mark is for :/

[gawdn]

Hey,

This is a 2013 HSC multiple choice question. You see I recognise it as one of faraday's first motors but I don't understand how to determine the direction of rotation. Would appreciate some help.