Science & Mathematics - 4 October 2007

I am wanting to do a science project on producing biogas (methane) using anaerobic digestion of wastewater on a laboratory scale.

1.) What materials would I need to do a small-scale version of this process in the laboratory?

2.) Are there any specific temperature requirements?

3.) What other environmental conditions are necessary?

4.) Can you get a reasonable yield using a sample of wastewater with algae and other bacteria present in the wastewater sample?

5.) Any insight as to how this experiment should be set up?

2007-10-04 08:40:41 · 1 answers · asked by Confused about life 2 in Biology

What are the chemical and physical properties of the fourth period metals ? up to Mn. So k , Ca, Sc, Ti, V, Cr, and Mn? how do i predict these properties?

2007-10-04 08:40:26 · 2 answers · asked by Anonymous in Chemistry

so this is a prime example of what i don't know how to do....

y=1/(1+e^(1/x))

how can i tell what the discontinuities are without using a graphing calculator?

2007-10-04 08:39:39 · 4 answers · asked by Brews 2 in Mathematics

A personal stereo costs £44.50 + VAT. If the rate of VAT is 17 and a half %, Calculate the total cost of the stereo.

2007-10-04 08:36:26 · 5 answers · asked by codysmithxo 1 in Mathematics

2007-10-04 08:35:06 · 6 answers · asked by newbie4_z 1 in Engineering

what is sin(2arcsin(3/5))?

i know that without the 2 it would simply be 3/5 but i can't find any examples with a co-efficient in front of the arcsin

2007-10-04 08:35:03 · 2 answers · asked by wiczyman 5 in Mathematics

What topic does global waming go under?

Cells
Biochemistry
Evolution
Bological technology
Viruses/bacteria
ecology
Biological energy process
cell reproduction
genetics

...and why does it go under that topic?

2007-10-04 08:32:45 · 4 answers · asked by Brittany B 2 in Biology

Suppose you drop a 20 pound weight and a 10 pound weight What will land first??

2007-10-04 08:22:26 · 10 answers · asked by Jhouston 1 in Astronomy & Space

Hi,

I know that copper can be turned to gold through nuclear reactions, but it only fomrs a radioactive/unstable isotope this way. This question is referring to alchemy being possible or not.

2007-10-04 08:21:06 · 6 answers · asked by J Money 1 in Chemistry

Here we go. We tested an unknown substance for reducing sugars, using the standard Benedict's reagent. The only thing we suspected was in the solution was aspartame. Strangely enough, the substance produced a dark blue colour at the end of the test, significantly darker than the original turqouise benedict's colour. Suspecting contamination, we ran it twice more, and found the same results. Any ideas?

2007-10-04 08:17:50 · 1 answers · asked by Anonymous in Chemistry

The equations of two planes p1 and p2 are 3x + 4y = 7 and 2x - y + 2z = 1. Find
(i) the distances from the origin and from the point A(4,-3,0) to the plane p1.
(ii) the Cartesian equations of the set of points whose distances from the plane p1 are equal to the distance of the point A from the plane p1.
(iii) a vector equation of the line of intersection of the planes p1 and p2.

2007-10-04 08:13:06 · 2 answers · asked by plolol 2 in Mathematics

y = x ²

2x-4y= -12

Could you provide workings as well, but please put your answer first so I can attempt it reach this answer.

With trial and error I found that:
x = 2
y= 4

However, I would like a method because I cannot continue doing trial and error - unless that's the method =?

2007-10-04 08:12:03 · 5 answers · asked by ??? 2 in Mathematics

1. A block of mass 6 kg, which has an initial
speed of 2 m/s at time t = 0, slides on a
horizontal surface.
Calculate the work W that must be done
on the block to bring it to rest. Answer in
units of J.

2. If a constant friction force of magnitude
10 Newtons is exerted on the block by the
surface, find the acceleration of the block in
absolute value. Determine the speed v of the block as a function of the time t. Answer in units of m/s2.

2007-10-04 08:08:09 · 1 answers · asked by Anonymous in Physics

Math question on the study guide I can't get for the life of me:

9] The height of an incomplete pass thrown by W. Paddock can be modeled by (3 pts each)
y(x) = -0.024x2 + 1.39x + 6
where y(x) is the height of the ball x feet from the W. Paddock.

(a) At how many feet from W. Paddock does the ball hit the maximum height?
(Round to the nearest foot)

(b) What is the maximum height that the ball reaches?
(Round to the nearest foot)

(c) How far is the point at which the ball hits the ground from the W. Paddock?
(Round to the nearest foot)

Thanks for any help.

2007-10-04 08:07:43 · 4 answers · asked by Ghost 1 in Mathematics

Jimmie is building a sandbox that is 12 times as wide as it is deep, and 1m longer than it is wide. It holds 3m^3 of sand when full. The wood cost $24/m^2. How much will the wood cost Jimmie? (btw, there is no top or bottom, just the sides when calculating for the area!!) (that the question...now i got the answer $84....is that right??? if so, can someone confirm that? if not , how would you get the correct answer....) ?? thanks!!

2007-10-04 08:01:31 · 3 answers · asked by Anonymous in Mathematics

10 points to whoever help me the most (and no i'm not cheating i'm asking for help/an explanation on how to work it out).


x(3x-2y)+y(3x-4y)

2007-10-04 07:58:04 · 8 answers · asked by Alicia ... 2 in Mathematics

from time to time, a light will float from 3 oclock to 6 oclock in my right eye, or from 12 to 3. less often the same things happen in my right eye from 12 to 9 and 9 to 6. Also, i sometimes see hundreds of tiny dots floating around in bright spaces. has anyone else had similar experiences? am i crazy?

2007-10-04 07:52:18 · 14 answers · asked by nacsez 6 in Other - Alternative

2007-10-04 07:46:00 · 5 answers · asked by Trouble 3 in Astronomy & Space

I'm sure they have radar so they can look ahead but if there is warnings out there do they just stop and wait the weather out, or just pray for the best and move threw it?

2007-10-04 07:41:33 · 5 answers · asked by shell bell 1 in Weather

If f(x)=4tanx/x

Find f'(x)

2007-10-04 07:41:03 · 5 answers · asked by Rachel 1 in Mathematics

what is the difference between that and a hoyt sector model?
a concentric zone model? the sector model?how could i apply it to my town, St Albans?

http://maps.google.co.uk/maps?near=st+albans&q=multi+map&f=p&rl=1

2007-10-04 07:35:07 · 3 answers · asked by Anonymous in Geography

We can see in some museums of history the weapons which men used in warfare even 150 yrs back are so big and heavy that now a normal man can only dare to lift.. Maybe humans are one of the rarest creatures facing problems of obesity, and have to do heavy workouts to build up, whereas animals are naturally born strong..

2007-10-04 07:28:48 · 6 answers · asked by vista rhyme 1 in Biology

Why is carbon dioxide bad for our Earth?
Why is it good?

2007-10-04 07:24:45 · 1 answers · asked by Anonymous in Botany

The y-intercept of the parabola described by y = 2(x - 5)2 + 6 is?

2007-10-04 07:23:30 · 3 answers · asked by Anonymous in Mathematics

A quadratic function passes through the point (3, -28) and has a vertex at (6, -64). Write the function in the form y = a(x - p)2 + q. What are the values of a, p and q?

2007-10-04 07:19:05 · 4 answers · asked by Anonymous in Mathematics

I am 36 year old male.
It started a very long time ago,I can feel something around me,and when I actually focus myself on the presence,I get a tingly sensation all over my body..like right now...Its not a scarey presence but a peaceful one.Also when I get upset, I think of the presence and I get the tingly sensation again,but I calm down very very fast.What is this?I can also feel when someone or something is in the room.I also have this feeling of that I should be doing something more with my life.Is this my Spirit Guide helping me...telling me what to do?Its not frightning.But when I was in the Army, about 12 years ago,I was in the barracks sleeping,and I awoke to hear inauduble voices in my room.My arms where frozen while laying on my back straight in the air.Then another voice told me that "Yaweh" will protect you.My hands dropeed and I fell asleep.After that incident is when I have been in tune with this presence.Any feedback would be helpful.
30 minutes ago - 3 days left to ans

2007-10-04 07:13:18 · 12 answers · asked by JDEVITA 2 in Other - Alternative

Right? Sooo then, how often do we have a totally new nose? And how often do our bone and cartilage cells replace each other? And do the cells ever change what they are replacing? Instead of copying exactly what the DNA says to, do they ever do something else? And what power does the brain/mind have over the cells?

2007-10-04 07:06:33 · 5 answers · asked by soccer_girl 1 in Biology

2007-10-04 07:03:55 · 3 answers · asked by RogerDodger 1 in Mathematics

a motor is rated at 2238W and is 93% efficient . how much power must be supplied to the motor?

2007-10-04 07:02:59 · 3 answers · asked by slim8880 1 in Mathematics

a) 1/24
b) 1/12
c) 1/8
d) 1/9
e) 2/9

2007-10-04 06:58:59 · 12 answers · asked by Smoothann 2 in Mathematics