Science & Mathematics - 18 November 2007

differentiate the function:
f(u)= ln u / (1+ln(2u))

The answer is f'(u)= (1+ln2) / u(1+ln(2u))^2
but I have no idea how to get it!! Thanks!

2007-11-18 18:33:17 · 2 answers · asked by Anonymous in Mathematics

i've looked up in a few books but haven't exactly got the def. of momentum.if someone could just give me the right explanation it'd be very helpful to me.
thanks.

2007-11-18 18:27:27 · 7 answers · asked by Anonymous in Physics

2007-11-18 18:26:04 · 3 answers · asked by Anonymous in Physics

The apothem of a regular pentagon is 10.8 centimeters.

a) Find the radius of the circumscribed circle.
b) What is the length of a side of the pentagon?
c) Find the perimeter of the pentagon.

2007-11-18 18:24:07 · 1 answers · asked by Roy Poomiwatracanont 1 in Mathematics

ring moving to ring

2007-11-18 18:13:07 · 3 answers · asked by sundeep 9732 1 in Astronomy & Space

2007-11-18 18:12:42 · 2 answers · asked by W.C.Y90 2 in Mathematics

How is it possible that if u exceed light speed you go back in time? Like In The 1800s we may have said if we exceed mach 5 we would find ourself back in time. Einstein clearly was a genius But im finding it hard to believe that part.A theory that i beleive in is hyperspace.If u exceed the speed of light you enter into hyperspace

2007-11-18 18:11:02 · 6 answers · asked by youngfranchi 2 in Physics

hmmm

2007-11-18 18:05:13 · 12 answers · asked by Yvonne 4 in Paranormal Phenomena

Log 10^-7 = x.?
Does x = 1 or
Does x = -7 ?
Or something else?

2007-11-18 18:03:39 · 8 answers · asked by Jeremy B 2 in Mathematics

I want to know about the career prospectus of B.Tech I.T. and B.Tech computer science and engineering. which branch promises a better future.

2007-11-18 17:48:38 · 1 answers · asked by h4saint 1 in Engineering

equilibrium

2007-11-18 17:43:03 · 9 answers · asked by dgIII 1 in Physics

i sometimes take sleeping pills at 50mg but one doesnt work..the box says one but i think i need more..but i dont want to overdose.

2007-11-18 17:42:25 · 3 answers · asked by Anonymous in Medicine

I am a medical school student. I know that many of you people find this question shocking and somewhat controversial. I would be interested in getting real bones as in my opinion it is essential to study from a real "life model" as it's the most accurate. Plastic ones just don't do it.
Anyway, is it even legal to sell such things?
Thanks for your help!

2007-11-18 17:39:00 · 2 answers · asked by Miss baby 1 in Biology

My first aid class was asking and I couldnt tell them. I know this can happen but I dont know what sort of poisoning can produce the effect whereby the body becomes lethal to others

2007-11-18 17:37:26 · 1 answers · asked by Anonymous in Chemistry

Which of the following reasons accounts for the fact that dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?
A) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause death of the embryo.
B) Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
C) Many lethal recessive alleles cause enhanced disease resistance when they are present in the heterozygous state, and carriers of these alleles have more children, on average, than other people.
D) The presence of a lethal dominant allele causes sterility.
E) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles.

2007-11-18 17:28:59 · 2 answers · asked by Jocelyn M 1 in Botany

How would I set this up and solve it?

2007-11-18 17:26:56 · 2 answers · asked by Jessca Hershlag 2 in Chemistry

2007-11-18 17:21:05 · 4 answers · asked by lady 3 in Medicine

2007-11-18 17:16:29 · 2 answers · asked by aprilfaithmanabat 1 in Botany

And can you show me how you solve it??

also this one too:

how many atoms are contained in 1.65 moles of copper metal?

2007-11-18 17:09:09 · 3 answers · asked by Anonymous in Chemistry

2007-11-18 17:07:37 · 1 answers · asked by epa51starnet 1 in Physics

my point is , how do we know somthing is there when were not looking at it AND how do we prove it? we cannot prove it NO MATTER what!!!!

when i was small (11 years old ) i used to wonder, did my toys move around when i slept and go EXACTLY back to there places 5 minutes before i woke up and look at them (the time before i wake up is not relative)....i know, i had a big imagination, BUT dont laugh at me, and dont say a camera is the solution, for the princible works just the same ( the moon reapears when the camera points at it)...


so is the moon really there whn we dont look at it?

2007-11-18 17:06:48 · 12 answers · asked by Anonymous in Astronomy & Space

A sample of gas has a volume of 4.25 L at 25.6 °C and 748 mmHg. What will be the volume of this gas at 26.8 °C and 742 mmHg?

v = 4.299 is this right??

2007-11-18 17:06:41 · 1 answers · asked by Anonymous in Chemistry

Is Minimi just the Belgium name of the gun or does it stand for something more or means something?

2007-11-18 17:02:36 · 4 answers · asked by Hands off my money 1 in Other - Alternative

the question is :
determine whether the series is absolutely convergent, conditionally convergent, or divergent

http://i181.photobucket.com/albums/x85/ctti_3/1195433439Xuj_Page_4-1.jpg

2007-11-18 17:01:02 · 2 answers · asked by ruby 2 in Mathematics

25v^2+60v+27

2007-11-18 16:47:25 · 4 answers · asked by Anonymous in Mathematics

If they exist, find the x, y, and z intercepts of the line x=24+7t, y=4+t, z= -20-5t.

(the answer to this was that the x intercept was -4)

how do i get to the answer?

2007-11-18 16:43:46 · 4 answers · asked by internet nickname 1 in Mathematics

i take it for insomnia

2007-11-18 16:42:23 · 2 answers · asked by Anonymous in Medicine

Here's a fun one: it is possible to divide a (circular) pizza with n cuts into more than 2n pieces (not necessarily equal, and the cuts do not all go through the center or bisect the pizza).

- the ordinary way, n cuts all through the center gives 2n uniform pieces and it is trivial to make them equal size.

However the MAXIMUM number of pieces p(n) for n cuts is called the lazy caterer's sequence and goes like this: 1, 2, 4, 7, 11, 16, 22, 29...
See e.g. the Wikipedia picture of the pancake cut into 7 pieces by 3 cuts (the middle piece is a (possibly equilateral) triangle)
http://en.wikipedia.org/wiki/Lazy_caterer%27s_sequence
Note: "equal-area" does NOT imply "uniform"!

So anyway my questions are these:
a) for n cuts, define the general algorithm to make the cuts
b) what is the ratio r(n) of largest to smallest pieces area?
Try e.g. computing r(3) and r(4)
c) is there a more useful sequence of cuts such that 2n

2007-11-18 16:41:24 · 2 answers · asked by smci 7 in Mathematics

thanks if you can help.

(3) superscript -2x = ( 1/5) timesx (27) superscript x

the 3 is in parenthesis the negative 2 x is superscript =equals= one fifth in parenthesis times 27 in parenthesis with x as a subscript.
ahhhhhhhhhhhhhhhhhhhhhhhhhhhhh thanks

2007-11-18 16:31:39 · 4 answers · asked by Boo Radley 4 in Mathematics

say heat flow is being modelled by the temperature in the xy-plane is given by:
T(x,y)=x*y - x

I've found the general directional derivative at the point (2,2), and the direction that temperature changes most rapidly from there, and now i'm being asked this:

If heat flow is a direction -∇T, express this as a differential equation in y and x and solve it. I'm sure I could solve it but I don't understand how you find the differential equation. how do you express it as one?

please help!

2007-11-18 16:30:29 · 1 answers · asked by mongrel73 1 in Mathematics