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Author Topic: Physics Discussion HERE ONLY!  (Read 33149 times)

Offline Diablo

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Re: Physics Discussion HERE ONLY!
« Reply #225 on: June 06, 2009, 03:39:13 pm »
How did you guys get the 1/8 fraction?

Step by step please?

Wasn't it the second answer over the first answer (54000?)
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #226 on: June 06, 2009, 03:41:17 pm »
ok 1 st ans was 540000 J!!

agreed!!
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #227 on: June 06, 2009, 03:44:47 pm »
now 4 the 2nd question!!!

the said 10% of ke...
so...10/100x540000=54000J

OK!!!!!!!!

NOW POWER=WORKDONE/TIME TAKEN

SO WORKDONE=KE

HENCE 54000/1
CUZ TIME WAS 1 SECOND!!!!!!

SO ANS=54000W OK
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Offline cherrip

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Re: Physics Discussion HERE ONLY!
« Reply #228 on: June 06, 2009, 04:50:55 pm »
they accept efficiency rule too  instead of power= energy\time ??? ??
for th fraction part , i calculated kinetic energy for half h wind speed and calculated output energy by muliplying by 10%
second answer\first one = 0.125 which is 1\8...
what fractions dd u get??
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #229 on: June 06, 2009, 05:13:04 pm »
i git 1/8 wat abt u
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #230 on: June 06, 2009, 05:16:39 pm »
IT IS 11 HRS NOW SINCE I JOINED THE FORUM AND MY REP IS -12!!!!!!!!!!!!!!!!!!

THIS IS DEVASTATING  ...............

AM  I RUDE........................


OR R U GUYZ JEALOUS.................????

WHY WHY WHY......

CUZ IT IS VERY "DE-MOTIVATING"  >:( >:( >:(
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Offline leebux101

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Re: Physics Discussion HERE ONLY!
« Reply #231 on: June 06, 2009, 05:20:42 pm »
Quote from: MR.BooMBastiC on June 06, 2009, 05:16:39 pm
IT IS 11 HRS NOW SINCE I JOINED THE FORUM AND MY REP IS -12!!!!!!!!!!!!!!!!!!

THIS IS DEVASTATING  ...............

AM  I RUDE........................


OR R U GUYZ JEALOUS.................????

WHY WHY WHY......

CUZ IT IS VERY "DE-MOTIVATING"  >:( >:( >:(
yes ur rude!!!!!!!!!!! y do u have to keep bragging abt how good u did....and demotivating for u??!! its demotivating for us, more like!!!!!!!!!! if it wasnt for the fact tht i dont minus ppl's rep, then i wud have definitely done urz!!!
« Last Edit: June 06, 2009, 05:24:32 pm by Bakhtawar »
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #232 on: June 06, 2009, 05:29:31 pm »
OK.WELL..............AS U CAN SEE ABOVE I ONLY TRIED TO EXPLAIN THE ANS MR.BAKHTAWAR......

AND JUST CUZ U HAD DA WORST PHY PPR3 IT DOESNT MEAN EVERYONE  ELSE HAS...no offence.....


anywaz if i hav said something wrong i APOLOGIZE...


R U GUYZ HAPPY KNOW!!!!!!!!!!!!!!!! ;D ;D ;D ;D ;D ;D :o ;) :D :)
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Offline leebux101

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Re: Physics Discussion HERE ONLY!
« Reply #233 on: June 06, 2009, 05:34:13 pm »
it a she By the way...and stop bragging...thts all we're asking...ok...and i may have had the worst paper and all my other papers may have been the best but u dont see me bragging , do u??? and u dont see anyone else bragging how well they did...do u??and oh plz!! u were not just explaining a question..maybe on this topic but not on other topics....anyways wish u luck for all ur exams...and hope u do really well..as well as u expect....
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #234 on: June 06, 2009, 05:38:00 pm »
XXXXCUSE ME......BRAGGING!!!!!!!!!!!!!!

I NEVER SAID MY PAPER WENT THE BEST ETC......

I JUST SAID IT WAS OK

I NEVER BRAGGED!!!!!!!!
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Offline leebux101

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Re: Physics Discussion HERE ONLY!
« Reply #235 on: June 06, 2009, 05:40:07 pm »
Quote from: MR.BooMBastiC on June 06, 2009, 05:38:00 pm
XXXXCUSE ME......BRAGGING!!!!!!!!!!!!!!

I NEVER SAID MY PAPER WENT THE BEST ETC......

I JUST SAID IT WAS OK

I NEVER BRAGGED!!!!!!!!
yeah ok wutever.....but i am sure the ppl who did minus ur rep had a good reason....besides .....seriously it duznt even matter....its just a stipid rep...its not ur real world rep....who cares...anyways where r u from??
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Offline MR.BooMBastiC

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Re: Physics Discussion HERE ONLY!
« Reply #236 on: June 06, 2009, 05:52:28 pm »
SOUTH africa!!!!!

Johannesburg!!!!!
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Offline leebux101

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Re: Physics Discussion HERE ONLY!
« Reply #237 on: June 06, 2009, 05:54:23 pm »
dude...seriously...relax...big deal man its just a rep tht duznt count....lol...relax...i dont get y ppl are fussed over this rep so much....
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Offline goin4dakill

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Re: Physics Discussion HERE ONLY!
« Reply #238 on: June 06, 2009, 07:13:25 pm »
Quote from: MR.BooMBastiC on June 06, 2009, 05:52:28 pm
SOUTH africa!!!!!

Johannesburg!!!!!


ME TOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Well, half at least :)
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Offline zmnigcse

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Re: Physics Discussion HERE ONLY!
« Reply #239 on: June 06, 2009, 08:23:37 pm »
Erm, man the windmill question was a little depressing  :'(

Anyway, what I did was.. erm

It's hard to recollect  ::)

I guess there was a question before the one where we had to find the mass, where they asked us to find out the power... shwoing all your calculations
Using the efficiency percentage they gave as 10%, I calculated the Energy as 54,000 Joules.
THEN, the E=Pt P= E divided by T. 54000/1 = 54,000 W (watts)

Then, erm, I was really confused for the next one.
I thought about using the Energy formula itself like KE= 0.5 mv2
but then i thought.. if the velocity is halved, how would the mass increase  :-\ cuz technically if the velocity decreased, then the mass of air passing through the turbines should fall...
... So I just used a ratio and got an answer I can't seem to remember  ???

BUT I think I'm wrong. As they said earlier, probably a heavier mass would mean that speed has decreased  :-[
BUT I DID get the fraction as 1/8... These two answers were really difficult   >:(
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