some1 noe answer for the last question (1 Viewer)

jarro_2783

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yes that is correct. Was that the one with the protons. You were meant to use the two force equations to end up with mv = qBr or something like that.
 

ying123123

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okay this is wat i got
dont think if its right
centripetal force (the result had and radius so yeah)
and f=qvb
mv=p
then p=qrB
 

Captain Gh3y

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Ok, here's how it worked:

(i) The particle is in a magnetic field, and also has centripetal force (the hint was 'circular path with radius...')

so F = qvB = mv²/r

Rearranging that, you get mv = qBr.


(ii) All of the values for the above were given, except for q, which is 1.602x1019C (from data sheet), so simple substitution to get the mass of a proton, as observed by someone standing outside the accelerator and watching it move.

(iii) Apply the mass dilation formula in reverse, ie.
mv = mo/√(1-v²/c²)
mv is what you found in part (ii), so rearranging
mo = mv*√(1-v²/c²)

Then you substituted in the velocity and your answer to part (ii), and got a mass, a bit smaller than the value in part (ii).
 

Haku

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i ran out of time and didn't get any of that. couldn't think when i am short on time....
 

thunderdax

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The answer for (iii) should have matched with the data sheet to 3 significant figures.
 

thunderdax

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yeah, it was 1.67e-27 which is the same as the data sheet to 3 significant figs.
 

richz

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Captain Gh3y said:
Really?

My final answer for (iii) was similar to seadonkey's, somewhere near 1.66e-27... can't remember exactly.
yeah, it was eql to 1.666e-27 so 3SF = 1.67e-27
 

jake2.0

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how come no one here took into account the weight force on the proton???

mind you i ended up getting the same answer
 
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woot! i got it!! gee it reli made me dive into equations and think to integrate these stuff together...:D
 

samaccount123

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Particle accelerators aren't THAT small..I didn't understand this qstn much to get it I think..
 

samaccount123

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Particle accelerators aren't THAT small..I didn't understand this qstn much to get it I think..
Oh yeah, darn..its travelled in a bubble chamber even though the cyclotron or something is as big as it is and the hydrogen deflects the proton/s..ugh
 

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