Author Topic: Another question - HELP!  (Read 8533 times)

Offline hasan919

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Another question - HELP!
« on: May 15, 2011, 10:00:58 am »
http://www.xtremepapers.me/CIE/Cambridge%20IGCSE/0580%20-%20Mathematics/0580_w05_qp_4.pdf

PG 6 - number 7) c) ii)... anyone can help me wid diz one? Thank You.

Offline SauD~

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Re: Another question - HELP!
« Reply #1 on: May 15, 2011, 10:17:39 am »
There is a formula for that which is...

Flow of water(volume) = Cross sectional area x speed x time
as we are required to find the time thus the formula changes into:

Flow of water (volume)/Cross sectional area x speed = time

now use the formula to find answer i will post it after i do the whole question :)

Offline Most UniQue™

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Re: Another question - HELP!
« Reply #2 on: May 15, 2011, 10:23:03 am »
There is a formula for that which is...

Flow of water(volume) = Cross sectional area x speed x time
as we are required to find the time thus the formula changes into:

Flow of water (volume)/Cross sectional area x speed = time

now use the formula to find answer i will post it after i do the whole question :)

By cross sectional area u mean the area of the of the circle(whole pipe) or the semi circle(half pipe)?

Offline SauD~

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Re: Another question - HELP!
« Reply #3 on: May 15, 2011, 10:36:18 am »
By cross sectional area u mean the area of the of the circle(whole pipe) or the semi circle(half pipe)?
Yes.. :)

Offline Most UniQue™

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Re: Another question - HELP!
« Reply #4 on: May 15, 2011, 10:47:49 am »
Yes.. :)

I'm asking u mean whole circle or semi?

Offline SauD~

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Re: Another question - HELP!
« Reply #5 on: May 15, 2011, 10:52:34 am »
I'm asking u mean whole circle or semi?
Yea, i told you its a formula.. that is

Flow of water(volume of whole water) = Cross sectional (volume of the pipe) x Speed x time

can you solve the answer.. i am unable too. in Mark scheme they aren't using the speed in calculation :-\

Offline Most UniQue™

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Re: Another question - HELP!
« Reply #6 on: May 15, 2011, 11:11:09 am »
Yea, i told you its a formula.. that is

Flow of water(volume of whole water) = Cross sectional (volume of the pipe) x Speed x time

can you solve the answer.. i am unable too. in Mark scheme they aren't using the speed in calculation :-\

No I'm doing m/j 2010 atm

Offline SauD~

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Re: Another question - HELP!
« Reply #7 on: May 15, 2011, 11:15:51 am »
No I'm doing m/j 2010 atm
ok.. do it later :)

Offline hasan919

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Re: Another question - HELP!
« Reply #8 on: May 15, 2011, 11:23:24 am »
i keep gettin 436 =/ diz is so confusin =[

Offline SauD~

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Re: Another question - HELP!
« Reply #9 on: May 15, 2011, 11:32:38 am »
i keep gettin 436 =/ diz is so confusin =[
I do  = 1512m3/ .00687m3 x .14m/s = 157205/ (60 x 60 x24) = 18.195 :(

according to mark scheme they do:
 1512m3/6870cm3 = 0.220087 x 1000000 = 220087/ (60 x 60 x 24)

i don't know why they at beginning divide a m3 with cm <-- impossible
then don't know why they multiply with 1000000 -.-
 
:-\

Offline NotAbod

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Re: Another question - HELP!
« Reply #10 on: May 15, 2011, 11:34:46 am »
I do  = 1512m3/ .00687m3 x .14m/s = 157205/ (60 x 60 x24) = 18.195 :(

according to mark scheme they do:
 1512m3/6870cm3 = 0.220087 x 1000000 = 220087/ (60 x 60 x 24)

i don't know why they at beginning divide a m3 with cm <-- impossible
then don't know why they multiply with 1000000 -.-
 
:-\
i will explain this part
they divided m3 by cm3, and he multiplied by 100^3 which is 1000000, to conver that m^3 to cm^3

Offline NotAbod

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Re: Another question - HELP!
« Reply #11 on: May 15, 2011, 11:36:04 am »
(1512*100^3) / 6870.
muliplied by 100^3 to convert m^3 to cm^3.

Offline SauD~

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Re: Another question - HELP!
« Reply #12 on: May 15, 2011, 11:37:44 am »
(1512*100^3) / 6870.
muliplied by 100^3 to convert m^3 to cm^3.
where will speed go?
why not included? :-\

isn't the formula
"low of water(volume) = Cross sectional area x speed x time "

Offline NotAbod

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Re: Another question - HELP!
« Reply #13 on: May 15, 2011, 11:38:52 am »
where will speed go?
why not included? :-\

isn't the formula
"low of water(volume) = Cross sectional area x speed x time "

i just explained, why did they multiply by 1000000

5mins lemme solve it

Offline SauD~

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Re: Another question - HELP!
« Reply #14 on: May 15, 2011, 11:46:08 am »
i just explained, why did they multiply by 1000000

5mins lemme solve it
Take your time,
If you have doubt search the formula over net ;)