Author Topic: additional maths...igcse...o-level....  (Read 13561 times)

Offline vaan

  • Newbie
  • *
  • Posts: 30
  • Reputation: 34
  • Gender: Male
  • wana go...on a death rid......
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

  • SF Citizen
  • ***
  • Posts: 190
  • Reputation: 219
  • Gender: Male
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 ???
Son, if you really want something in this life, you have to work for it. Now quiet! They're about to announce the lottery numbers

Offline slvri

  • SF Master
  • ******
  • Posts: 1773
  • Reputation: 1735
  • Gender: Male
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
i hate A level...........

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
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?
divine intervention!

Offline sameer210394

  • SF Citizen
  • ***
  • Posts: 190
  • Reputation: 219
  • Gender: Male
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 »
Son, if you really want something in this life, you have to work for it. Now quiet! They're about to announce the lottery numbers

Offline sameer210394

  • SF Citizen
  • ***
  • Posts: 190
  • Reputation: 219
  • Gender: Male
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..,.  ;)
Son, if you really want something in this life, you have to work for it. Now quiet! They're about to announce the lottery numbers

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
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
divine intervention!

Offline slvri

  • SF Master
  • ******
  • Posts: 1773
  • Reputation: 1735
  • Gender: Male
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
i hate A level...........

Offline sameer210394

  • SF Citizen
  • ***
  • Posts: 190
  • Reputation: 219
  • Gender: Male
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
Son, if you really want something in this life, you have to work for it. Now quiet! They're about to announce the lottery numbers

Offline ~~~~shreyapril~~~~

  • SF Master
  • ******
  • Posts: 2606
  • Reputation: 2640
  • Gender: Male
  • "Prototype"
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!!
Friendship is like peeing on yourself. Everyone can see it but only you get the warm feeling that it gives :D :P :)

Offline vaan

  • Newbie
  • *
  • Posts: 30
  • Reputation: 34
  • Gender: Male
  • wana go...on a death rid......
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

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
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 »
divine intervention!

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
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

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: additional maths...igcse...o-level....
« Reply #13 on: November 10, 2009, 09:17:29 am »
it takes hell lotta time though.
divine intervention!

Offline ~~~~shreyapril~~~~

  • SF Master
  • ******
  • Posts: 2606
  • Reputation: 2640
  • Gender: Male
  • "Prototype"
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???
Friendship is like peeing on yourself. Everyone can see it but only you get the warm feeling that it gives :D :P :)