General Thoughts: Physics (3 Viewers)

[egnaro315]

The projectile motion question was really ambiguous. Do we just assume the base of the house is the maximum height or does the projectile reach the maximum height then fall towards the base of the house. I got stuck on that part so I just assumed the base of the house is the max height lol makes it easier.

 

[luke0410]

That was the whole point, you have to imagine that the particle is stationary and the anode is moving towards it, not the other way around. So if it asked from an observers perspective then it would contract but from the electrons perspective it would increase.
Bad example but if youve ever seen star trek or something and as soon as they start travelling at light speed (which is impossible but whatever) all of the stars stretch out around them, because everything around them gets longer.

no

 

[oh well]

oh right, exam's over, get the fuck over it, go pepper your angus for CHEM!

 

[cheepy5]

Someone at the BOS plays angry birds.
Overall not bad, the validation of theories question was pretty random.
Astro was alright, i kinda like how they basically put all the calculations in the 6 marker instead of having to write a 8 marker on something

 

[luke0410]

look at 2006 hsc physics q 25 c) it is the reverse to our question but the point being, in the frame of the electron, length is contracted

 

[LlamaBoi]

no

whatever helps you sleep at night

 

[IceDingo]

That was the whole point, you have to imagine that the particle is stationary and the anode is moving towards it, not the other way around. So if it asked from an observers perspective then it would contract but from the electrons perspective it would increase.
Bad example but if youve ever seen star trek or something and as soon as they start travelling at light speed (which is impossible but whatever) all of the stars stretch out around them, because everything around them gets longer.

If you were standing on the electron (lol) you would see the world contract as it passes you at 3x10^7 m/s. From the electron's frame of reference you are observing the distance you are travelling.

This is pretty cool. Say you had a 40 cm ruler (R1) travelling at 3x10^7 m/s that goes past another 40 cm ruler that is stationary (R2). Now R1 would see R2 travelling past at 3x10^7 m/s and applying length contraction, would see the length of R2 as 39.8 cm. But R2 would see R1 travelling past at 3x10^7 m/s. When you use the length contraction formula, you find that the length of R1 from R2's frame of reference is also 39.8 cm.

 

[Boozil]

urgh if it was from the electrons frame of reference, then there would be no change since the laws of physics hold true in an inertial frame of reference. (remain 40cm)

+1

 

[akandas]

what was the question asking?

 

[jeffwu95]

for the tower question did you guys say that A or B hit the ground first

 

[akandas]

that validity question was out of the ordinary, but it was a pretty fair exam. expecting 65 raw. I MISSED THE FUCKING QUESTION 30 BEHIND THE LOUDSPEAKER QUESTION!!!

what was it asking?

 

[cookeemonstah]

I think this is wrong based on not being able to assume Vy = 0 when it hits?

pretty sure the projectile stopped when it reached delta y

 

[RishBonjour]

for the tower question did you guys say that A or B hit the ground first

I said B was in geo orbit lol. probably wrong. But A CERTAINLY hit ground first.

and Llamaboy (haha- nice name) - think about it from the electron's perspective. If you were on the electron, to you, you are stationary, the space infront of you is MOVING TOWARDS YOU at relativistic speed --> hence it contracts.

 

[gayforniall]

Some of the questions were really horribly worded and they made me cry. I hated the tower question and the transformer question.

 

[LlamaBoi]

I said B was in geo orbit lol. probably wrong. But A CERTAINLY hit ground first.

and Llamaboy (haha- nice name) - think about it from the electron's perspective. If you were on the electron, to you, you are stationary, the space infront of you is MOVING TOWARDS YOU at relativistic speed --> hence it contracts.

haha I dont even know anymore...just gonna leave it cause you cant change it now and no point dreading about it
still found it to be a good exam though

 

[lance687876]

what was it asking?

how would i know?

 

[MonsterMe]

pretty sure the projectile stopped when it reached delta y

Yeah, I wasn't disputing that... But delta Y isn't the maximum y value? It's just the change in Y. I didn't think you could assume that the point of impact was the center of the parabola.

 

[EinstenICEBERG]

too many questions does not ask specifically, so therefore there could be many cases for several questions as in from what point of view, are they asking at..

anyone can be right, if they state at what view they are answering the question.

 

[RishBonjour]

haha I dont even know anymore...just gonna leave it cause you cant change it now and no point dreading about it
still found it to be a good exam though

yep. time for assassins creed. enjoy bos


as long as I get around 80 raw. i will be content. (looks pretty bad so far)

 

[cookeemonstah]

Yeah, I wasn't disputing that... But delta Y isn't the maximum y value? It's just the change in Y. I didn't think you could assume that the point of impact was the center of the parabola.

yeh.... i understand, that makes it slightly trickier then