Science & Mathematics - 29 June 2007

I need to amplify the output getting from a microphone which is around 5mV (millivolts)

Its enough for me to amplify it to about 2 or 3V

But i need some IC or even transistor amplifying circuit that will first amplify the very small output of mic to a reasonable one so that I can amplify that voltage by using few common IC's or transistors.
But plss help me by giving an IC which can accept such small voltage levels and amplify them...

Thanks in advance...would be of great help if you answer without delay...
once again thank you.

2007-06-29 20:52:37 · 3 answers · asked by haridravid 2 in Engineering

a) solve for all values of x that statisfies the equation. b) Graph the functions y =x and y = 2 squareroot x onthe same graph (by plotting points if necessary). Show the points of intersection of these two graphs.

2007-06-29 20:46:50 · 2 answers · asked by Sheri C 1 in Mathematics

2007-06-29 20:45:30 · 16 answers · asked by Anonymous in Astronomy & Space

The cost of producing a number of items x is given by C mx  b, in which b is the fixed cost and m
is the variable cost (the cost of producing one more item).

(a)

If the fixed cost is $40 and the variable cost is $10, write the cost equation.

(b)

Graph the cost equation.

2007-06-29 20:16:10 · 3 answers · asked by Dave 4 in Mathematics

2007-06-29 20:14:22 · 1 answers · asked by elac 1 in Botany

Hi there,

I'm trying to learn about electronics, mainly for soldering purposes and I can't seem to understand the resistors colour code system, on this webpage here http://www.doctronics.co.uk/resistor.htm it states that this is the numbering system,

Number Colour
0 black
1 brown
2 red
3 orange
4 yellow
5 green
6 blue
7 violet
8 grey
9 white

you supposedly work out resistors like this, let's say you have a resistor with brown, black and red colour bands it would go, 1 for brown, 0 for black, and then add two noughts for the red (it's a multiplier), so you'd be left with 1000...correct? ..so then you take off the noughts again, and you'd have a 10K resistor, however...in one of my soldering kits it has a brown, black and red resistor yet it's referred to as a 1K resistor, instead of 10K like some different resistors in my book, does that mean that the manual is wrong? or the 0 isn't counted as a number? I can't seem to understand

2007-06-29 20:02:34 · 6 answers · asked by pyrokinetic_666_666 2 in Engineering

I got the answer $107, 35.44 This is not one of the answers what am I doing wrong? please hurry taking a timed test!

2007-06-29 19:47:39 · 8 answers · asked by Flagstaff mama 2 in Mathematics

I'm looking for a calculator to help me add and mostly subtract time in the hour:minute:second format. Something either online or that I can run on my computer off line. Best would be a formula I could insert into a spreadsheet - Microsoft Works.

2007-06-29 19:45:00 · 4 answers · asked by swm_seeks_sf 3 in Mathematics

2007-06-29 19:44:42 · 15 answers · asked by Life goes on... 6 in Astronomy & Space

to keep them for a long time. I have save all of them on dvd format. The thing is i sometimes when i open up a folder some of the photos cannot be seen. You can see the fils but when open with ACDsee i can see out of 40 only 25. Can any one please help.

2007-06-29 19:33:59 · 2 answers · asked by jurassic3228 2 in Earth Sciences & Geology

we need it badly...we're having a research about ethanol as gasoline extender...if possible, please suggest web sites that can contribute to our research...

2007-06-29 19:19:55 · 2 answers · asked by yeah_boy 2 in Other - Science

We always measure the amount of changes by time and also we refer that changes to time, is that really happens in our actual life?

2007-06-29 19:18:53 · 3 answers · asked by M.Ali 2 in Physics

2007-06-29 19:17:52 · 8 answers · asked by Anonymous in Astronomy & Space

9^x+^2 = 240 + 9^x

2007-06-29 19:16:11 · 6 answers · asked by knlwin 1 in Mathematics

2007-06-29 19:15:23 · 4 answers · asked by DINESH GAUR 1 in Astronomy & Space

i mean geographic features like u shape valley
it should be clearly that in which course

2007-06-29 19:11:45 · 4 answers · asked by Anonymous in Earth Sciences & Geology

If the universe was to be a shape, wouldn't it make the most sense that it was round? Everything in the universe seems to be Round, the atoms are round the planets are round, they spin around, the galaxies spin around, it's all circular like motions, even the atoms move around in a circular motion. wouldn't it be odd if the universe itself was circling around a bunch of other things? maybe something Huge we don't even know about?

2007-06-29 19:09:22 · 12 answers · asked by Anonymous in Astronomy & Space

here's the link

http://www.sciencecourseware.org/VirtualEarthquake/php/Seismograms.php

choose southern california
then answer the questions

2007-06-29 19:06:49 · 0 answers · asked by morningmorning 1 in Earth Sciences & Geology

the plane y + z =3 intersects the cylinder x^2 + y^2 = 5 in an ellipse. Find the parametric equations for the tangent line to this ellipse at the point (1,2,1)
Additional Details

Well i believe i let x = cost and y=sint and z=3-sint but then do i take the derrivate of each and then just plug in the point? it seems to straight forward. please help.

2007-06-29 19:01:29 · 2 answers · asked by Anonymous in Physics

2007-06-29 19:00:34 · 5 answers · asked by Anonymous in Mathematics

Using Shockley's diode equation, determine the diode current at fora silicon diode with Is (saturation current) = 0.1 x10-6 A at a reverse-bias potential of -10V. Is the resul expected? Why?

2007-06-29 18:55:43 · 0 answers · asked by Anonymous in Engineering

On his way from suburb A to surburb B, the bus driver kept to the speed of 44km/h. When he arrived at B, he found out he needed to hurry to be back in A on time. So he drove the bus at a constant speed of 66km/h on the way home along the same route. What speed did he need to keep constant during the whole trip so that it would take the same amount of time.

The answer might be 55, but my tutor says it might not be, so I'm confused.

2007-06-29 18:54:01 · 6 answers · asked by Elder Price 2 in Mathematics

please..i really need help...thanks!

2007-06-29 18:51:51 · 3 answers · asked by Sofia 1 in Chemistry

What observation can make about the successive partial sums of this sequence? In particular, what number does it appear that the sum will always be smaller than?
Answer:
Terms Sum

1
1, 1/3
1,1/3,1/9
1,1/3,1/9,1/27

2007-06-29 18:50:55 · 8 answers · asked by Sheri C 1 in Mathematics

if so why is the earth thriving with life and the moon so dead? since both these bodies are so greatly close to one another on the cosmic scale and the sun make life possible on earth why not the moon too?

2007-06-29 18:43:59 · 8 answers · asked by Anonymous in Astronomy & Space

Ok I can't use the interactive sky chart, I've downloaded java and this is still all that displays: http://img146.imageshack.us/img146/812/problemqx2.png

2007-06-29 18:29:30 · 3 answers · asked by ? 3 in Astronomy & Space

i am able to prove it only for acute angles in various quadrants. not obtuse ie. the ones starting all the way from the 1st quadrant.

plas help:)

thanks

and also, could you give me the proof for sin(-theta) = -sin theta and cos(-theta) = cos theta for angles that are not acute?

thanks:)

2007-06-29 18:20:21 · 3 answers · asked by tut_einstein 2 in Mathematics

2007-06-29 18:16:38 · 7 answers · asked by Anonymous in Biology

2007-06-29 18:13:27 · 6 answers · asked by Anonymous in Zoology

typical day for a hospital nurse consistss of what? I know they get "report" ...then what do they do?
Check vitals? Deliver food trays? Bed Baths?

2007-06-29 18:06:26 · 11 answers · asked by Anonymous in Medicine