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Physics Unit 4 JUNE 11/6/12

How well did you do on the exam?


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i ned 2 revise 4 hubbles constant and also stars a bit. i still hve sme ques's im unable 2 solve:( and nuclear physics lil only and thermal phy also i hve 2 read once again and thts all wat i can do
i see... kinda same situation eh? ;)
Which questions btw? Lemme see if I can help with those maybe....
 
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Q(58) in astrophysics i don kno even if we hve 2 kno abt tht and Q(66) last part :)
In Q58 which part do u wanna know?
The last part is just that we need to put both the fields equal, and find R
like GM/R^2 = Gm/r^2 and then solve for R :)

and 1 more que Q(67) in astrophysics whn they ask abt ratio thnx alot:) bt plz send me the way 4 ths ans
for this 1 we need to use g = GM/r^2 so 400 times less massive means mass is less by 400 but r is inc by (15)^2 ; 225/400 = 9/16
(is that correct btw? :unsure:)
 
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i wrote it ths way can u tel me where is my mistake
u can substitute an do it, but why do the hassle when u can use simple ratio :p But either way is fine IF u dont mess up where u substitute the numbers ;)

btw.. confirm my answer pls... m not completely sure...
 
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In Q58 which part do u wanna know?
The last part is just that we need to put both the fields equal, and find R
like GM/R^2 = Gm/r^2 and then solve for R :)


for this 1 we need to use g = GM/r^2 so 400 times less massive means mass is less by 400 but r is inc by (15)^2 ; 225/400 = 9/16
(is that correct btw? :unsure:)
yes it is :)ok is my way correct?and i hve doubt on the 1/225 bcz i cancelled the rest so can i take reciprocal or no?> and can u send me the way u did it?
 
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yes it is :)ok is my way correct?and i hve doubt on the 1/225 bcz i cancelled the rest so can i take reciprocal or no?> and can u send me the way u did it?
yes it is ;) I did it just like I wrote it there :p n yeah u need to take a reciprocal cuz its inversely proportional :)
 
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hmm how can u plz jst show me cuz i fel wat i wrote is wrng isn't it?
Its not wrong... i umm.. dunno how to do it ur way :oops:
I jst did it by reasoning it... If it is 400 times less mass, then divide by 400 (inversely related) , if it is 15 times nearer, then multiply by 15^2 (directly related)
225/400 = 9/16 :)
 
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Its not wrong... i umm.. dunno how to do it ur way :oops:
I jst did it by reasoning it... If it is 400 times less mass, then divide by 400 (inversely related) , if it is 15 times nearer, then multiply by 15^2 (directly related)
225/400 = 9/16 :)
bt i thnk we must show our way ryt? u kno i hve prb wth maths thts y im affraid if i tok reciprocal 4 1/225 and i left 400 down its wrng so im confused i'll send u the working i did and show u clearly wat i mean
 

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bt i thnk we must show our way ryt? u kno i hve prb wth maths thts y im affraid if i tok reciprocal 4 1/225 and i left 400 down its wrng so im confused i'll send u the working i did and show u clearly wat i mean
well, imma right it just like what I wrote there :p
U have done it right BUT u need to bring the 400 up, thats taken as a reciprocal too :)
 
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