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Comments:
<0> relik: but it's not that it changes from one to the other
<0> relik: it's always a particle and always a wave
<0> relik: it's just different experiments expose different aspects of it
<1> :-)
<0> relik: in fact there are experiments in which it's both simulatanously
<2> oh god
<0> relik: i mean, experiments in which you are to treat it as both to explain it
<3> ok
<0> relik: one way to view it
<0> relik: is that you have lots of parallel universes
<0> relik: say a photon strikes a piece of gl***
<0> relik: the universe splits into 2 universes. In one, the photon goes through, and in the other, it bounces off the gl***
<3> hmmm
<0> relik: the universes can interact with each other
<3> that is very hard to prove i ***ume 0.0
<0> relik: you can't prove anything
<0> stop saying that
<4> PENIS
<5> its just a way of viewing it
<5> a way of understanding the probabilistic nature
<3> you are talking like physics is some kind of religion
<3> merely a believe -.-
<0> relik: no
<0> relik: you look at the evidence, and chose the simplest explanation that fits the evidence
<0> of course the word 'simplest' is hard to define :-)
<0> "god did it" is short and simple, but not what we mean by simplest :-)
<0> relik: you cannot prove even the simplest parts of say gravity
<0> relik: if I drop a cup and it falls, you cannot prove that if i drop a different cup, that it will also fall
<0> unless you actually test that
<3> it is all about probability
<0> right. we cannot prove the sun will come up tomorrow
<3> when i hear about parallel universes
<3> for some reason i feel the need to smack my head on the monitor
<5> the parallel universes thing is just a way to think about it
<3> i don't think it would be a highly probably option
<5> but when it comes down to it
<0> bleech: i don't entirely agree. there might be some way to test that
<5> its really just trying to visualize what the Feynman path-integral formulation is all about
<0> bleech: we may, for example, find a way to jump between different parallel universes etc
<2> JohnFlux: i have to add 5 vectors, which method is 'better': head to tail them, simply adding all their components...?
<0> anubiss: what's the difference?
<0> anubiss: as long as your space is flat
<2> the result will the same i think
<2> its flat
<0> it will in flat space
<6> Hello, I'm trying to prove that in a vertical circular motion using a rope, (the weight of rope can be neglected), the tension in the uppest point (C) is greater from the tension in the lowest point (A) in 6 times the weight of the body (m).
<2> 2d
<0> anubiss: number of dimensions doesn't matter
<0> anubiss: use whichever you're more comfortable with
<2> well there are angles, its a bit messy on a coordonate plan
<0> anubiss: ah i see
<6> I started with: T_a = m( (v_a)^2/R+g) and T_c= m( (v_c)^2/R-g)
<0> anubiss: your vectors are expressed as angle, length ?
<2> no, say their angles are all relative to 0, is it the same as adding them head to tail ?
<2> yup
<2> angle, units
<0> anubiss: you need to convert to x,y first
<2> but here like...wait
<0> then add them
<5> relik: you dont like the parallel universe idea?
<2> http://img443.imageshack.us/my.php?image=phy1lb1.jpg
<2> ther'e drawn like that on my quiz sheet
<6> T_a/T_c = ((v_a)^2 + Rg)/((v_c)^2 -Rg)
<0> relik: the truth is, that we honestly don't really know what is going on fundamentally
<2> relik: and that is good news
<0> relik: so currently the different ways of thinking about it are all equivalent
<6> Then got this equation from energy conservation, (v_a)^2-(v_b)^2 = 4Rg
<6> I'm not sure how to go on
<0> relik: maybe one day we'll find out that one way is more correct than others
<2> JohnFlux: take a look when you have some seconds to spare
<0> imageshack is being really slow these days
<0> it's even been down some days
<0> anubiss: i can't view it, but i ***ume it's just in polar coordinates. you have 2 vectors that you want to add
<0> in angle, length
<2> 5 vectors
<2> they are not on a coordinate plan
<2> they are drawn seperately
<0> okay
<2> so i can: put them all on a coordinate plan then find their components, or add them up head to tail and mess with the angles
<2> i dont know which one is better
<0> by "coordinate plan" I think you mean in cartesian coordinates
<2> yup
<5> has anyone here ever used vtk before?
<0> anubiss: i think you'll end up doing the same caculations either way
<2> ill stop thinking and start drawing then
<0> anubiss: for a vector (theta,r)
<0> anubiss: what's it's x and y coordinates ?
<0> (i.e. convert from polar coordinates to cartesian coordinates)
<2> x is r cos theta
<2> y is r sin theta
<2> relative to x axis
<0> so if you have two vectors: (theta1, r1) and (theta2,r2) what's the x and y of the two added together?
<2> addition
<2> x's together
<2> y's together
<0> so (r1 cos theta1 + r2 cos theta2, r1 sin theta1 + r2 sin theta2)
<2> yes
<0> so you should be able to quite quickly do that to find x and y for all 5 added together
<0> so generally, ( sum r_i cos theta_i , sum r_i sin theta_i )
<6> anyone? :(
<2> what if the angle is 0 on x or 0 on y
<2> nvm
<2> thats fine for the first quadrant
<2> if i have a quadrant 2 vector ?
<2> its still sin and cos ?
<0> eXistenZ: (v_a)^2-(v_b)^2 = 4Rg i guess you meant v_c ?
<2> or i have to change something?
<6> JohnFlux, Oh, yes, sorry.
<0> anubiss: i think it still works out
<6> JohnFlux, I wonder what is still missing.
<0> eXistenZ: okay so v_a^2 = 4RG - v_c^2
<2> like one is 50 degrees relative to negative x axis
<6> JohnFlux, ja
<2> so 180-50 130
<2> okok
<0> [22:15] <6> T_a/T_c = ((v_a)^2 + Rg)/((v_c)^2 -Rg)
<0> actually let's do: v_c^2 = 4RG - v_a^2
<0> eXistenZ: right?
<6> JohnFlux, yup
<0> so substitute that into the line I pasted
<6> (v_c^2+5Rg)/(v_c^2 - Rg)
<0> no sorry, substitute in our v_c^2 = one
<6> JohnFlux, but v_a^2 - v_c^2 = 4Rg
<0> sorry
<0> yeah
<0> one sec
<0> eXistenZ: "the tension in the uppest point (C) is greater from the tension in the lowest point (A) in 6 times the weight of the body (m)."
<0> eXistenZ: I'm not sure what you mean by this
<6> JohnFlux, T_c/T_a = 6mg
<0> eXistenZ: you mean: T_a = T_c + 6mg ?
<6> erm sorry
<6> T_a/T_c = 6mg
<0> reread the question you're asked
<6> JohnFlux, I should've said that the tension in the lowest point is greater.
<0> I think it wants you to show that: T_c = T_a + 6mg
<0> I think it wants you to show that: T_a = T_c + 6mg grrr
<0> eXistenZ: what does the question say exactly
<6> Let me translate it directly.
<6> JohnFlux, A boy spins a small ball that is tied to a rope in a vertical circle. The m*** of rope is negligent in relation to the that of the ball. Show that the tension of the rope in the lowest point is greater than the tension in the highest point in 6 times the weight of the ball.
<0> "Show that the tension of the rope in the lowest point is greater than the tension in the highest point in 6 times the weight of the ball."
<0> I think the correct translation is:
<0> "Show that the tension of the rope _at_ the lowest point is greater than the tension _at_ the highest point _by_ 6 times the weight of the ball."
<0> i.e. T_a = T_c + 6mg
<7> standard problem
<6> Possibly :)
<6> Let me try it now
<0> eXistenZ: :-)
<6> JohnFlux, For my silly mistakes, thank you for your patience and sincere help!
<0> eXistenZ: np
<0> T_a = m( (v_a)^2/R+g)
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