Author Topic: additional maths...igcse...o-level....  (Read 13248 times)

Offline vaan

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additional maths...igcse...o-level....
« on: November 09, 2009, 12:03:21 pm »
hey ppl...put ur add.math question here...n hope dat me...or some1 else 'll help..... ;) :)

Offline sameer210394

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Re: additional maths...igcse...o-level....
« Reply #1 on: November 09, 2009, 12:51:53 pm »
hey ppl...put ur add.math question here...n hope dat me...or some1 else 'll help..... ;) :)


A plane flies due north from A to B a distance of 1000 km, in a time of 2 hrs. During this time a steady wind, with speed of 150 km/h, is blowing from the south-east. Find the direction in which the plane must be headed.

i hav solved this question, but need more practice in it, so du u have any note for such type of questions, and wat do u call this type of questions, which chapter are these questions frm ???
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Offline slvri

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Re: additional maths...igcse...o-level....
« Reply #2 on: November 09, 2009, 01:21:16 pm »

A plane flies due north from A to B a distance of 1000 km, in a time of 2 hrs. During this time a steady wind, with speed of 150 km/h, is blowing from the south-east. Find the direction in which the plane must be headed.

i hav solved this question, but need more practice in it, so du u have any note for such type of questions, and wat do u call this type of questions, which chapter are these questions frm ???
these are relative velocity questions. i know theyre hard, theyre real b*tches...........anyways
VP=1000/2=500 kmh-1
VW=150 kmh-1
the direction the plane must be steered in is of VP/W
the relative velocity equation is VP=VP/W+VW
refer to diagram attached
theta is the angle that the plane must be steered on
using the cosine rule
cos45=(5002+1502-Vp/w2)/2(500)(150)
Vp/w=407.96kmh-1
using the sine rule
150/sin theta=407.96/sin45
theta=15.1degrees
bearing is 015.1degrees
sorry for the sh*tty diagram but my drawing sucks in Paint
hope this helped
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Offline Ghost Of Highbury

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Re: additional maths...igcse...o-level....
« Reply #3 on: November 09, 2009, 02:34:26 pm »
hey slvri, just 1 doubt, isnt 500km/h the velocity of plane relative to wind? because after the wind is blown it moves north rite?
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Offline sameer210394

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Re: additional maths...igcse...o-level....
« Reply #4 on: November 09, 2009, 03:01:51 pm »
hey slvri, just 1 doubt, isnt 500km/h the velocity of plane relative to wind? because after the wind is blown it moves north rite?

arrey the answer is right. read the quest carefully n u will c that the plane travels 1000 km, and while traveling this distance the wind is also blowing...

therefore there 2 forces acting, 1 of the plane and one of the wind to travel the 1000 km distance.

Now this results in a vector where the total velocity ( 1000/2 = 500 Km/h ) equals the velocity of plane in still air and the velocity of wind.

thus:    this form a triangle as drawn by slrvi where AB is 500Km/h. 

i hope this is clear.

 
« Last Edit: November 09, 2009, 03:04:17 pm by sameer210394 »
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Offline sameer210394

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Re: additional maths...igcse...o-level....
« Reply #5 on: November 09, 2009, 03:05:48 pm »
these are relative velocity questions. i know theyre hard, theyre real b*tches...........anyways
VP=1000/2=500 kmh-1
VW=150 kmh-1
the direction the plane must be steered in is of VP/W
the relative velocity equation is VP=VP/W+VW
refer to diagram attached
theta is the angle that the plane must be steered on
using the cosine rule
cos45=(5002+1502-Vp/w2)/2(500)(150)
Vp/w=407.96kmh-1
using the sine rule
150/sin theta=407.96/sin45
theta=15.1degrees
bearing is 015.1degrees
sorry for the sh*tty diagram but my drawing sucks in Paint
hope this helped


dude i knew the answer,

but appreciated any which ways..,.  ;)
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Offline Ghost Of Highbury

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Re: additional maths...igcse...o-level....
« Reply #6 on: November 09, 2009, 03:15:26 pm »
abbe dude...i know the answer and triangle law..just wanted to confirm the Vp/w

lol, if u knew the answer y did u ask! :P :P
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Offline slvri

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Re: additional maths...igcse...o-level....
« Reply #7 on: November 09, 2009, 04:52:39 pm »
nope.........Vp is the velocity of the plane and its the true or actual speed with which the plane travels........it says that the plane goes north at 500kmh-1 so the true velocity is 500kmh-1
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Offline sameer210394

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Re: additional maths...igcse...o-level....
« Reply #8 on: November 09, 2009, 06:06:55 pm »
abbe dude...i know the answer and triangle law..just wanted to confirm the Vp/w

lol, if u knew the answer y did u ask! :P :P


i wrote, that i knew the answer (upak dekh). i jus wanted 2 know wat chapter is this frm...   :P
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Offline ~~~~shreyapril~~~~

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Re: additional maths...igcse...o-level....
« Reply #9 on: November 10, 2009, 03:46:30 am »
ohh..!!
this is from relative velocity and vectors!!!

i thought you wud know this!!
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Offline vaan

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Re: additional maths...igcse...o-level....
« Reply #10 on: November 10, 2009, 08:26:55 am »
question...no..6..m/j 07...paper2...can some1 help me.. :-\.i tried a lot of times but could not find my mistake out....now im confused :-\

Offline Ghost Of Highbury

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Re: additional maths...igcse...o-level....
« Reply #11 on: November 10, 2009, 08:47:40 am »
\frac{d}{dx}\left(x^2ln x\right) = 2xln x + x
\int 2xln x+ x\,dx = x^2ln x
\int 2xln x + \int x = x^2ln x
\int 2xln x = x^2ln x - \frac{x^2}{2}
2\int xln x = x^2ln x - \frac{x^2}{2}
2* 2\int xln x = 2 * x^2ln x - \frac{x^2}{2}
4\int xln x = 2x^2lnx - x^2
\int 4xln x = 2x^2lnx - x^2
applying the limits
^e_1(\int 4xln x) = 2e^2 - e^2 - 0 - 1
^e_1(\int 4xln x) = e^2 + 1
 
« Last Edit: November 10, 2009, 09:05:46 am by A@di »
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Offline astarmathsandphysics

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Re: additional maths...igcse...o-level....
« Reply #12 on: November 10, 2009, 09:15:48 am »
nice to see latex being used. The answer is right too

Offline Ghost Of Highbury

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Re: additional maths...igcse...o-level....
« Reply #13 on: November 10, 2009, 09:17:29 am »
it takes hell lotta time though.
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Offline ~~~~shreyapril~~~~

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Re: additional maths...igcse...o-level....
« Reply #14 on: November 10, 2009, 09:44:53 am »
why cant we have the symbol for integration ready???
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