MedVision ad

Search results

  1. D

    hardest chem questions

    people did and you told them that it wasnt hard
  2. D

    Black Body Radiation

    And for those who do care and cant be bother to look it up, I will explain it briefly, simply and in an analogous yet erroneous fashion: According to the second law of thermodynamics, entropy of a closed system will not decrease. Given the scale of the universe, it would then seek to equally...
  3. D

    Physics marathon 2011

    Name a metal, metal alloy and a ceramic superconductor and identify their critical temperatures Metal - Lead - superconducting at 7K Alloy - Nickel-titanium - Superconducting below 23K Ceramic - YBaCuO - Superconducting at temperatures below 77k. I pose a physics history question...
  4. D

    v for vendetta, related text for power

    I tend too look at power through the lense of what gives individuals/institutions authority. IN this case, its a hearts/minds thing Force - Totaliterian state, you'll find evidence everywhere in the text Ideas - Again, strong motive , for winning British hearts and minds. note conflict between...
  5. D

    God has no merit

    TRUST. You took this topic into a pisshole for religions, you pathetic atheist bigot. We have threads for that already, and we dont need you to necro them. Necrophilia is against religious law and your precious 'secular' law. More importantly; 1. God defies logic (by definition, as god =...
  6. D

    Preliminary mathematics marathon

    d/dx (sqrt(x^3+3x+2)^2) thats the differiencial by above working, should be right i think. Denominator gives crit value i think (speculating, correct me if I'm wrong?) Never mind, I AM wrong.
  7. D

    Preliminary mathematics marathon

    y=|x| Piecemeals a good idea perhaps? x>1 y=x y'=1 x<1 y=-x y'=-1 x=0 y'=? so y=(x^2)^1/2 thats abolsute value y=|x| y'=((2x)*1/2)(y) y'= y/x y'=((x^2)^1/2)/x Thats my proof for wolfram's answer I just d/dx 'd wrong. I mean y' = 2x*1/2*(x^2)^(-1/2) y'=x*1/x note numerator is...
  8. D

    Differential equations

    I'm going to go and do some implicit differentiation now, because I just realised that I have forgotten it (OH THE HORRRRRORS IN STORE FOR ME!)
  9. D

    Preliminary mathematics marathon

    Wolfram told me it was so and so it was.
  10. D

    Preliminary mathematics marathon

    Reading above posts, i think thats a bit odd the signum rule gives no indication for x=0 does it for y=|x|?
  11. D

    Preliminary mathematics marathon

    Hmm, for y=|x| at x=0 the gradient is undefined isnt it? Because y'(x) = sqrt(x^2)/x Therefore cannot divide by 0? </pre>
  12. D

    Differential equations

    ah, i didnt think of that. Nice. I'm useless without a piece of paper :p :uhhuh::uhhuh::uhhuh::uhhuh:
  13. D

    Differential equations

    What? Then you'd get something strange with 2 variables in a and x, and that cant be solved with a single eqn as I recall? a^2*e^ax+2(ae^ax)+e^ax=0? Unsolvable without 'a' value? so you cant really solve for y? You need a f(x) to solve any diff eqn, and it doesnt necessarily have to be...
  14. D

    Fertiliser prac urgent help

    File:Bariumsulfatpulver.png - Wikipedia, the free encyclopedia Heres some Barium Sulfate for you. Its white, milky white. Heres some Barium Chloride. File:Barium chloride.jpg - Wikipedia, the free encyclopedia hmmmm, that could be confusing! I lol at your teacher who probably thought...
  15. D

    Is this way of the Simpson and Trapezoidal rule correct for HSC or not?

    Yes, its right, and I use them too. They're from the extension section of the Cambridge book, as I recall?
  16. D

    Electron configuration + Valencies of transition metals

    Most are completly random but tend to be 2/3/4 as stated above. (given by later chemistry - just learn a few values) They should tell you their valency in Roman numerals for tests, as they are NOT part of the prelim course.
  17. D

    Heat of Combustion

    Welcome!
  18. D

    Heat of Combustion

    <table class="MsoNormalTable" style="border-collapse: collapse; border: medium none;" border="1" cellpadding="0" cellspacing="0"> <tbody><tr style=""> <td style="width: 77.4pt; border: 1pt solid windowtext; padding: 0cm 5.4pt;" valign="top" width="103"> Hydrocarbon<o></o> </td> <td...
  19. D

    Heat of Combustion

    COME BACK I WAS SLIGHTLY WRONG! See above word document for clearer points, and i reduced my arguement down to a few lines. Incomplete combustion still applies, thankfully. Use the q=m delta t equations to work out the energy released from the mass. Compare to theoretical calues, you know how...
  20. D

    Differential equations

    Dont worry it is in the Cambridge book, in Ch. 13 somewhere. y''+2y'+y=0 You have to use the other compoments of the question to solve this, btw. Exp. function is good for that.
Top