ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: thatisanote on June 13, 2011, 05:10:49 pm
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On the study design it says: qualitative description of air resistance. What does this mean we will need to know?
What, if anything, would we need to know about cantilever and suspension bridges?
Can anyone explain iTute 2011 q11 and 12?
VCAA 06, S&M, q11, why is it D?
P=Fv - can anyone give me a quick explanation of that? I'm not sure if we need it but explain anyway. Isn't it power to overcome friction or something like that? So power is force of friction times velocity?
With elevators, can we just work out a summary of what the apparent weight will be relative to the actual weight?
e.g. v=velocity, a=acceleration
v=up, a=down (slowing down): N?
v=up, a=up: N?
v=down, a=down, N?
v=down, a=up, N?
Anyone have a good example of a relative velocity question (eg relative velocity of a bird from a car) - can we be asked these?
Good example of a banking question?
And re theory on cheatsheet, I have:
-How banking a corner helps
-Something about apparent weight/weightlessness
-The opto-electric transformation thing
-Modulation/demodulation
And my exam techs
read and read the question!
write on diagrams
do what the question says
And anyone who's done TSSM 09 S&M, can you explain 11 and 12 a bit better for me?
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Do we have to use 10 m/s^2 as g?
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On the study design it says: qualitative description of air resistance. What does this mean we will need to know?
About air resistance we only need to know how it affects motion, but not how to do calculations involving it.
Basically stuff like:
Air resistance opposes the motion of the object.
Magnitude of air resistance increases as the object's velocity increases.
It will reduce the distance (horizontally + vertically) reached by a projectile.
It will slow down (horizontally + vertically) a projectile's velocity.
The time the object will be in motion will increase.
I'd assume we'd need to know about terminal velocity as well (when the air resistance and weight forces balance each other).
Anyone have a good example of a relative velocity question (eg relative velocity of a bird from a car) - can we be asked these?
Good example of a banking question?
The banking question in VCAA 2010 wasn't bad. But it was only about calculating the angle.
I'm pretty sure reference frames/relative velocity has been taken out of motion and put into special relativity.
Also:
Do we have to use 10 m/s^2 as g?
Why would you not want to use 10m/s^2 as g? It makes calculations quicker and easier in the exam.
edit: accidentally pressed post too early and cut out half my post :|
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Do we have to use 10 m/s^2 as g?
I don't think you will be penalised by using 9.8, however most of the questions will have 'nicer' answers when you use g=10. You may as well use 10:P
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Do we have to use 10 m/s^2 as g?
Nope, if you use 9.8 as g then can't say that it's wrong or else they're saying the entire worlds wrong about acceleration due to gravity but using 10 as g gives a nicer answer so stick with 10
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are you guys gonna use pen or pencil?
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Im using pencil for any graphs, and multiple choice. And pen for everything else :)
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On the study design it says: qualitative description of air resistance. What does this mean we will need to know?
About air resistance we only need to know how it affects motion, but not how to do calculations involving it.
Basically stuff like:
Air resistance opposes the motion of the object.
Magnitude of air resistance increases as the object's velocity increases.
It will reduce the distance (horizontally + vertically) reached by a projectile.
It will slow down (horizontally + vertically) a projectile's velocity.
The time the object will be in motion will increase.
I'd assume we'd need to know about terminal velocity as well (when the air resistance and weight forces balance each other).
Anyone have a good example of a relative velocity question (eg relative velocity of a bird from a car) - can we be asked these?
Good example of a banking question?
The banking question in VCAA 2010 wasn't bad. But it was only about calculating the angle.
I'm pretty sure reference frames/relative velocity has been taken out of motion and put into special relativity.
Also:
Do we have to use 10 m/s^2 as g?
Why would you not want to use 10m/s^2 as g? It makes calculations quicker and easier in the exam.
edit: accidentally pressed post too early and cut out half my post :|
Ok thanks, i've been using 9.8 ALL the time especially in Specialist Mathematics (which I think only uses 9.8), I'm so used to it I sometimes accidentally use it in Physics calculations alongside 10. I'll try to stick with 10 for the whole paper.
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Thanks guys. Any ideas on the other qs?
Also, use 10.
And the 2011 front page sample says to use black or blue pen for everything except multi choice.
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Well P = E/t
If your looking at this in terms of friction the energy change due to friction will equal the work done by friction
i.e Delta E = W = F(friction) x displacement
.: P= W/t
Honestly i wouldnt simplfy it any further as in my opinion dealing with work is simplier than velocity but:
(Fx)/t = F(friction)v = P
note that it is only the displacement in the direction of the force
I doubt you will encounter this to be honest.
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Thanks :)
Bumping for
With elevators, can we just work out a summary of what the apparent weight will be relative to the actual weight?
e.g. v=velocity, a=acceleration
v=up, a=down (slowing down): N<mg
v=up, a=up: N>mg
v=down, a=down, N<mg
v=down, a=up, N>mg
can anyone confirm those?
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Apparent weight and actual weight shouldn't have anything to do with velocity and its direction, and yes they seems correct to me