darksnowman Posted January 31, 2007 Share Posted January 31, 2007 I've a translation to do, English to French - "Immigration Energises our Economy." Sounds like fun doesnt it? I've read through it and it seems like there are gonna be two awkward parts: - Britain, a soft touch? Hardly. - The word underinvestment. Any groovy ideas would be appreciated. Link to comment Share on other sites More sharing options...
Problematique Posted January 31, 2007 Share Posted January 31, 2007 I'm doing Physics for chemistry. Hooray. i didn't do Physics at A level. Shit. Basically... "The C60 molecule is a sphere of diameter 1nm (10^-9m) with an ionisation energy of 7.5eV. Find the energy of photons which could eject electrons from C60 with a wavelength which would match the molecular size." I'm quite stuck because I'm not quite sure how to bend lambda = h/p. And the lambda = h/sqrt (2mk) doesn't help either. Stupid physics (sorry Chris! But I did do history instead which shows how badly I got on with the subject...) Link to comment Share on other sites More sharing options...
Ginger_Chris Posted February 1, 2007 Share Posted February 1, 2007 energy (joules) = h * frequency frequency = c / wavelenght energy (eV) = energy (joules)/e (as in 1.602*10^-19) thats the best i can think of at the moment. But it is 5am in the morning and I'm very tired. Stupid work. I can't remember any of the basic stuff. 7.5eV gives me about 165nm. so its not that. 1nm is about 1238eV. but i don't know, I don't do molecules. individual atoms only I'm afraid. Hyperfine energy levels of Hydrogen and Helium especially. sorry I can't help much. Link to comment Share on other sites More sharing options...
Problematique Posted February 1, 2007 Share Posted February 1, 2007 Oh, it's physics so it does't really matter whether it's molecular or not...it's all arbitrary. Thanks very much, you're a diamond. Link to comment Share on other sites More sharing options...
THE ganondorflol Posted February 1, 2007 Share Posted February 1, 2007 I have got RS homework, and really can't be bothered. I is about Judaism... consider yourselves lucky! Link to comment Share on other sites More sharing options...
The fish Posted February 1, 2007 Share Posted February 1, 2007 I have got RS homework, and really can't be bothered. I is about Judaism... consider yourselves lucky! What's so bad about Judaism compared to Christianity or Islam? Link to comment Share on other sites More sharing options...
Gentleben Posted February 1, 2007 Share Posted February 1, 2007 While it's not homework I'II like some help with a little language. How do I say in either Spanish or Iltalian. "Your presense is offending me and I wish you to leave" Link to comment Share on other sites More sharing options...
Shino Posted February 1, 2007 Share Posted February 1, 2007 While it's not homework I'II like some help with a little language. How do I say in either Spanish or Iltalian. "Your presense is offending me and I wish you to leave" Italian: "La tua presensa mi offende personalmente, e sarei grato se te ne andasi" Spanish: "Tu presencia me está ofendiendo y deseo ke sales " It's something like that. Link to comment Share on other sites More sharing options...
Charlie Posted February 1, 2007 Share Posted February 1, 2007 Anyone want to sit my sociology exam for me tomorrow? You'll also be able to go out and get pissed at the pub for me afterwards... Link to comment Share on other sites More sharing options...
Gentleben Posted February 1, 2007 Share Posted February 1, 2007 Italian: "La tua presensa mi offende personalmente, e sarei grato se te ne andasi" Spanish: "Tu presencia me está ofendiendo y deseo ke sales " It's something like that. Thank you. can't wait to try this out at work. Link to comment Share on other sites More sharing options...
Letty Posted February 4, 2007 Share Posted February 4, 2007 How would I factorise this? 4x^2 - y^2 Link to comment Share on other sites More sharing options...
DCK Posted February 4, 2007 Share Posted February 4, 2007 How would I factorise this? 4x^2 - y^2 If you mean 4x^2 = y^2 then it would make (square root both sides) y = 2x. Either that or I don't know what you're talking about You need 2 'x'es right? Link to comment Share on other sites More sharing options...
Supergrunch Posted February 4, 2007 Share Posted February 4, 2007 Yes, can you write out the original question? Link to comment Share on other sites More sharing options...
Letty Posted February 4, 2007 Share Posted February 4, 2007 The original question: 5.(a). Factorise 4x^2 - y^2. Link to comment Share on other sites More sharing options...
Supergrunch Posted February 4, 2007 Share Posted February 4, 2007 The original question: 5.(a). Factorise 4x^2 - y^2. (2x+y)(2x-y) Difference of two squares. Link to comment Share on other sites More sharing options...
Letty Posted February 4, 2007 Share Posted February 4, 2007 (2x+y)(2x-y) Difference of two squares. oh dear, that was far too obvious thank you Link to comment Share on other sites More sharing options...
DCK Posted February 12, 2007 Share Posted February 12, 2007 Ugh, some other hardcore nerd help me. If, in C++, you need to fill a boolean matrix with all 'true' values, then the right notation would be: bool check_table[6][4] = { { true } }; right? If that's true I need some aspirin, quickly. Link to comment Share on other sites More sharing options...
Goron_3 Posted February 18, 2007 Share Posted February 18, 2007 oh poo, i'm stuck on chemistry. I've drawn the different structural isomers of C5H12 but i need to put them in order of boiling point and explain why... Link to comment Share on other sites More sharing options...
Supergrunch Posted February 18, 2007 Share Posted February 18, 2007 oh poo, i'm stuck on chemistry.I've drawn the different structural isomers of C5H12 but i need to put them in order of boiling point and explain why... I think you'll find that the more rounded or branched they are, the lower the boiling point, as straight chain molecules can stack closer together and thus form stronger intermolecular forces, so more energy is required to break these forces. Link to comment Share on other sites More sharing options...
Goron_3 Posted February 18, 2007 Share Posted February 18, 2007 I think you'll find that the more rounded or branched they are, the lower the boiling point, as straight chain molecules can stack closer together and thus form stronger intermolecular forces, so more energy is required to break these forces. you're a legend I'm stuck on one more question though (last one though)... State a suitable reagent and conditons for the reaction of: Propene -> Propane. I'm guessing you name a catalyst or something...? Link to comment Share on other sites More sharing options...
Problematique Posted February 18, 2007 Share Posted February 18, 2007 you're a legend I'm stuck on one more question though (last one though)... State a suitable reagent and conditons for the reaction of: Propene -> Propane. I'm guessing you name a catalyst or something...? Yeah, basically you use a Nickel catalyst in an atmosphere of hydrogen to hydrogenate the alkene. 450K and 1MPa if silly A levels conditions knowledge serves me correctly. Link to comment Share on other sites More sharing options...
Strider Posted February 19, 2007 Share Posted February 19, 2007 Could someone explain to me how i would get to the answer for these please? Thanks Link to comment Share on other sites More sharing options...
Supergrunch Posted February 19, 2007 Share Posted February 19, 2007 1. I q = 2p - 5 II q = (p^2) + 10p + 7 2p - 5 = (p^2) + 10p + 7 (equate I and II) Rearrange and solve this quadratic for p, substitute the answer you get into either I or II for q. 2. I y = 4x + 4 II (x^2) + (y^2) = 36 (x^2) + (4x+4)^2 = 36 (substitute I into II) Multiply out and rearrange this, solve the resulting quadratic for x, substitute this value into I or II to find y. Link to comment Share on other sites More sharing options...
MoogleViper Posted February 19, 2007 Share Posted February 19, 2007 2. I y = 4x + 4 II (x^2) + (y^2) = 36 (x^2) + (4x+4)^2 = 36 (substitute I into II) Multiply out and rearrange this, solve the resulting quadratic for x, substitute this value into I or II to find y. I multiplied out the brackets and cancelled down. And got 17x^2 + 32x = 20. I then factorised and got x(17x+32)=20. I don't know where to go from here. EDIT: I've realised where I've gone wrong. Link to comment Share on other sites More sharing options...
Supergrunch Posted February 19, 2007 Share Posted February 19, 2007 I multiplied out the brackets and cancelled down. And got 17x^2 + 32x = 20. I then factorised and got x(17x+32)=20. I don't know where to go from here. EDIT: I've realised where I've gone wrong. You should always rearrange quadratics so that they are equal to 0, then try and factorise. If you can't factorise them, use the formula (or complete the square, which is effectively the same thing). Link to comment Share on other sites More sharing options...
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