# Recent content by dcl

1. ### Ultra high energy cosmic particles?

http://www.fourmilab.ch/documents/ohmygodpart.html Has some infomation of such high energy particels. It also briefly states how it was detected.
2. ### Stargazing New Scientist Article - Pendulums + Solar Eclipse

I'd love to see more infomation on this if anyone has any.
3. ### Projecting a vector onto a plane problem

Thanks for that, guess it was simpler than I thought. :)
4. ### Projecting a vector onto a plane problem

Heya's how would one go about spanning a vector say 'u' onto a plane spanned by vectors v1 and v2. I have a formula for projecting a vector onto say a subspace w: projw(u) = <u,v1>v1 + <u,v2>v2 + .... <u,vn>vn But I'm unsure how to use this for when I need to project the vector onto a...
5. ### Simple Gas mass/volume Question

Yer probably... Might be a type in the question.
6. ### Acid concentration Q's

Heya's Having some problems with the following question: Trimethylacetic acid C_4 H_{11} COOHis a weak monoprotic acid. When 0.0010 mol of Trimethylacetic acid was dissolved in 100mL of water, the concentration of trimethylacetic ion was found to be 3.0 \times 10^{ - 4} mol.L^{ - 1} a)...
7. ### Calculating Heat Of Combustion

OK, think I may have worked it out.. I got an answer of around 2747 kJ/mol, whereas my book gives the answer of 2740 kJ/mol.
8. ### Calculating Heat Of Combustion

Hey, I need some help with the following question: A sample of 0.1964g of Quinone (C6 H4 02, Relative Molar Mass = 108.1) was burned in a bomb calorimeter that heas a heat capacity of 1.56 kJ/M. The temperature in the caolorimeter rose from 19.3 to 22.5 degrees celcius. (a) write a...
9. ### Simple Gas mass/volume Question

The exhaust gas from a car is tested and found to contain 8% by volume of carbon monoxide. If the molar volume of CO at SLC = 24.4 L/mol, what is the mass of carbon monoxide in 1L of exhaust gas? I'm very new to these calculations and am unsure how to approach it.
10. ### Confusion about Gravitational Potential

I see, makes sense. Thanks for clearing that up.
11. ### Confusion about Gravitational Potential

Heya's Im a bit confused reguarding gravitational potential energy. I've seen 2 different calculations U(h) = mgh where h is the height above the ground. and U = -GMm/r (off the top of my head, havnt got my notes here with me right now) Could anyone help clear this up for me? Why...
12. ### Complex Integral

Stuffed up in the first step :( Thanks guys. :) prolly should goto bed now. :(
13. ### Complex Integral

Here is the problem: {\mathop{\rm Im}\nolimits} \int {e^{x(2 + 3i)} } dx One sec, I'm having another go at it. = {\mathop{\rm Im}\nolimits} \int {e^2 } e^{3ix} dx = {\mathop{\rm Im}\nolimits} \int {e^2 } [\cos (3x) + i\sin (3x)]dx \begin{array}{l} = \frac{{ - e^2 \cos...
14. ### Tangent Plane And Normal Vector.

Think I've worked it out for myself. Method was sorta wrong. Once I have Grad F, all I need to do is sub in the values of the point and It will give me the normal vector and from that I can work out the equation. I think thats right.
15. ### Tangent Plane And Normal Vector.

I'm having trouble working out the tangent plane of an equation at a specified point (4,1,-2) The equation being 9x^2 - 4y^2 - 25z^2 = 40 now \nabla f = (18x, -8y, -50z) yeh? Just reading off this should give us the normal vector shouldn't it? (18,-8,-50) and from that we can work out...