Class of 2025 (2025 HSC CHAT) (31 Viewers)

[notsmartenough]

i hate english so much why is this crap compulsory

 

[WeiWeiMan]

i hate english so much why is this crap compulsory

most important subject ngl

 

[C_master]

wdym 'ngl' it literally is

 

[notsmartenough]

most important subject ngl

my teacher is so bad i hate him so much he literally spends half the lesson doing "discussions" but its just him talking about his life stories

 

[eternallyboreduser]

Math and chem actually ontop the only 2 subjects i can stand/like

 

[Aeonium]

why is physics so hard bro like wtf

i agreee physics is so hard like what the heck my teachers so bad

which part about it specifically?

omg speaking of phys where can i find mod 2 harder questions?? ive done past papers so far but need moree because there arent that many yr11 papers

if you have friends who go tutoring they might have some good ones in there; if i remember i'll send some later

 

[JiffyVFX]

which part about it specifically?

if you have friends who go tutoring they might have some good ones in there; if i remember i'll send some later

Okay like I blame it on my teacher, he spent like an hour talking about calculating the change in velocity in two dimensions and I still don't get it and like my vector diagrams I swear the answers are always different to mine

 

[banigul@30]

Okay like I blame it on my teacher, he spent like an hour talking about calculating the change in velocity in two dimensions and I still don't get it and like my vector diagrams I swear the answers are always different to mine

how do you connect your vectors?

 

[JiffyVFX]

how do you connect your vectors?

Like yk v-u and then the u is minus so it gets flipped around but then my friend keeps telling me it's wrong and then I don't get like which way the resultant vector arrowhead is supposed to go

 

[banigul@30]

lols it is confusing but once you get the hang of it, youll do well

 

[JiffyVFX]

Does anyone have physics questions or a good place to get them because like my teachers slacking a bit and then he makes these google forms except that the questions make no sense and include content that we haven't learned yet

 

[banigul@30]

Like yk v-u and then the u is minus so it gets flipped around but then my friend keeps telling me it's wrong and then I don't get like which way the resultant vector arrowhead is supposed to go

idk if this helps, but you need to connect them from head to tail (like the head of the first one and the tail of the second one), and the resultant is always from the tail of your first vector to the head of your second. and when you are measuring the angle (in 2d) imagine the resultant vector coming from the origin of a cartesian plane

 

[Aeonium]

Okay like I blame it on my teacher, he spent like an hour talking about calculating the change in velocity in two dimensions and I still don't get it and like my vector diagrams I swear the answers are always different to mine

incoming yap fest:

okay so here's what i do personally (easier than tip to tail + cosine and more relevant to module 5)
so you can consider each vector kind of like a right angle triangle. you have TWO perpendicular components (cause phys only does 2d vectors)
so you want to break down each vector into and components using trigonometry.

for instance, a vector angled at 30 degrees above the horizon with a magnitude of, say, 45 can be broken down into the component parallel to the horizon and the component perpendicular to the horizon
.

for this, the perpendicular component is given by while the parallel component is given by . with this, you can sum all the perpendicular components and parallel components separately and use pythagoreas to get the resultant (make sure to inverse tan the components to get the final vector)

example:
vector a has a magnitude of 75 and is pointing at N30E, vector B has a magnitude of 30 and is pointing at S45W.

you can sum the horizontal components as such:

and then vertical:

and then to get the resultant vector, you use pythagoreas and inverse tangent for direction

i suggest this method for two reasons
1. it's easier when you have many different vectors (collisions in module 2)
2. you will decompose vectors anyways in module 5 for projectile motion
ALSO I LOWKEY FORGOT BEARINGS BUT LIKE I HOPE THIS MADE SENSE you can also make a table of the x and y components.
EDIT: PLEASE DO NOT FORGET YOUR AXIS LABELS LIKE I DID HERE I'M TOO CEEBS TO DO ANYTHING

 

[banigul@30]

incoming yap fest:

okay so here's what i do personally (easier than tip to tail + cosine and more relevant to module 5)
so you can consider each vector kind of like a right angle triangle. you have TWO perpendicular components (cause phys only does 2d vectors)
so you want to break down each vector into and components using trigonometry.

for instance, a vector angled at 30 degrees above the horizon with a magnitude of, say, 45 can be broken down into the component parallel to the horizon and the component perpendicular to the horizon
. View attachment 42620

for this, the perpendicular component is given by while the parallel component is given by . with this, you can sum all the perpendicular components and parallel components separately and use pythagoreas to get the resultant (make sure to inverse tan the components to get the final vector)

example:
vector a has a magnitude of 75 and is pointing at N30E, vector B has a magnitude of 30 and is pointing at S45W.
View attachment 42621
you can sum the horizontal components as such:

and then vertical:

and then to get the resultant vector, you use pythagoreas and inverse tangent for direction

i suggest this method for two reasons
1. it's easier when you have many different vectors (collisions in module 2)
2. you will decompose vectors anyways in module 5 for projectile motion
ALSO I LOWKEY FORGOT BEARINGS BUT LIKE I HOPE THIS MADE SENSE you can also make a table of the x and y components.
EDIT: PLEASE DO NOT FORGET YOUR AXIS LABELS LIKE I DID HERE I'M TOO CEEBS TO DO ANYTHING

how is this different from tip to tail?

 

[Aeonium]

how is this different from tip to tail?

oh the way i was taught tip to tail was you had to use cosine rule n allat
this gets you the same result it's just 'safer' in my opinion
you still tip to tail the result at the end but if you have like 5 vectors tip to tailed them normally it would be extremely painful

 

[Average Boreduser]

Like yk v-u and then the u is minus so it gets flipped around but then my friend keeps telling me it's wrong and then I don't get like which way the resultant vector arrowhead is supposed to go

my best advice is for you to not over think vectors- I had the same problem but once I learnt vectors from 3u this crap become comprehendible. note u dont have to know much 3u prelim content to learn it so like nothing is stopping u and u get basically the best from both worlds. + if ur scared to use vecs just use vector component addition. safest option by far as aneoniudfhskdfhsklah said be4

 

[Aeonium]

how is this different from tip to tail?

here is a screenshot from my #amazing (corrected) notes

 

[Aeonium]

Like yk v-u and then the u is minus so it gets flipped around but then my friend keeps telling me it's wrong and then I don't get like which way the resultant vector arrowhead is supposed to go

a negative vector implies it's just flipped 180 degrees (or the other way if you're doing 3d)
so just flip the vector around then add it

 

[banigul@30]

incoming yap fest:

okay so here's what i do personally (easier than tip to tail + cosine and more relevant to module 5)
so you can consider each vector kind of like a right angle triangle. you have TWO perpendicular components (cause phys only does 2d vectors)
so you want to break down each vector into and components using trigonometry.

for instance, a vector angled at 30 degrees above the horizon with a magnitude of, say, 45 can be broken down into the component parallel to the horizon and the component perpendicular to the horizon
. View attachment 42620

for this, the perpendicular component is given by while the parallel component is given by . with this, you can sum all the perpendicular components and parallel components separately and use pythagoreas to get the resultant (make sure to inverse tan the components to get the final vector)

example:
vector a has a magnitude of 75 and is pointing at N30E, vector B has a magnitude of 30 and is pointing at S45W.
View attachment 42621
you can sum the horizontal components as such:

and then vertical:

and then to get the resultant vector, you use pythagoreas and inverse tangent for direction

i suggest this method for two reasons
1. it's easier when you have many different vectors (collisions in module 2)
2. you will decompose vectors anyways in module 5 for projectile motion
ALSO I LOWKEY FORGOT BEARINGS BUT LIKE I HOPE THIS MADE SENSE you can also make a table of the x and y components.
EDIT: PLEASE DO NOT FORGET YOUR AXIS LABELS LIKE I DID HERE I'M TOO CEEBS TO DO ANYTHING

ohhhh i get what you mean now, yeah definitely never connect more than 2 vectors at a time, it gets wayy too complicated esp trying to make all the vectors keep their angle, always break it up and then resolve it, i was just confused cause this what we were taught as 'tip to tail' so i didn't know how it was different

 

[Aeonium]

ohhhh i get what you mean now, yeah definitely never connect more than 2 vectors at a time, it gets wayy too complicated esp trying to make all the vectors keep their angle, always break it up and then resolve it, i was just confused cause this what we were taught as 'tip to tail' so i didn't know how it was different

yeah components can never get the wrong answer if you define your directions properly and yet my friend & i lost a mark in the first prelim phys assessment because the teacher got a different answer somehow? and when asked, he couldn't even explain why