Science & Mathematics - 3 February 2007

2007-02-03 17:55:28 · 7 answers · asked by Anonymous in Botany

Idk what course to take in high-school.

2007-02-03 17:49:47 · 7 answers · asked by Anonymous in Chemistry

I am working on an open-source audio compression program and am trying to find a way to efficiently minimize the amplitude of a wave file, both for compression purposes and to make sounds modified with it put less stress on speakers.

Here's my mathematical dillemma:

Supposed you have two frequencies that last for about 1/10th of a second (IE a 2048 sample FFT window)...and you want to modify every other frequency to be rotated a certain amount of phase from the last frequency.
You are given first frequency is f1, second (f2) and magnitudes m1 and m2 to form an optimization equation that defines what phase relative phase angle (-180 to 180 degrees) would each phase START at relative to the other to minimize the peak amplitude of the combined signals.
As a precondition, though, the phasing should not reduce audibility of each frequency (IE no significant phase cancellation...at least to the point the human ear can hear both frequencies clearly)

2007-02-03 17:49:31 · 2 answers · asked by M S 5 in Physics

Please justify well.

2007-02-03 17:49:26 · 4 answers · asked by Leo 2 in Physics

Please justify well.

2007-02-03 17:48:46 · 6 answers · asked by Leo 2 in Engineering

Please justify well.

2007-02-03 17:48:29 · 4 answers · asked by Leo 2 in Physics

2007-02-03 17:46:39 · 6 answers · asked by Anonymous in Earth Sciences & Geology

Help! I need to know why a compound microscope inverts an image seen through the lens (so that if you move the object left it appears to go right) and why a stereoscopic microscope (also called large-object view microscope, at least by my professor) does not do this (hence when the object is moved lieft it appears to move left through the lens as well). Thanks!

2007-02-03 17:45:13 · 1 answers · asked by Anonymous in Physics

This is for general interest, NOT because I am planning to order it. My son is researching potential careers in his 8th grade class, and he has an interest in pyrotechnics. He's learned a lot about the school subjects, degrees, experience, training, and licenses required. He's found out some interesting careers he could pursue as a pyrotechnician. He's putting a career poster together for display at school. He's using RDX as one of his example chemicals, and would like to add catalog pages to his display; also provide the names of some scientific supply houses if possible.
Thank you for any help!

2007-02-03 17:37:07 · 1 answers · asked by purplesometimes 4 in Chemistry

Something related to exponents

2007-02-03 17:29:56 · 8 answers · asked by rajagopal r 1 in Mathematics

The xehibit must be easy to make and explain!

2007-02-03 17:29:25 · 5 answers · asked by Rahul P 1 in Engineering

Ive been working on this for a while and I cant seem to get the right answer:

A 100 W incandescent light bulb converts approximately 2.5% of the electrical energy supplied to it into visible light. Assume that the average wavelength of the emitted light is λ = 540 nm, and that the light is radiated uniformily in all directions.
How many photons per second, N, would enter an aperture of area A = 8 cm2 located a distance D = 5 m from the light bulb?

Ive determined that each photon has 2.3eV of energy, but I cant find the intensity

2007-02-03 17:18:23 · 1 answers · asked by Anonymous in Physics

I don't understand this maybe some one can help me out please;;)

2007-02-03 17:15:35 · 6 answers · asked by Anonymous in Weather

2007-02-03 17:13:05 · 2 answers · asked by Anonymous in Physics

the integral of x / (x^2 + 9) = ?

what do i do, a trigonometric substitution??

thanks in advance :)

2007-02-03 17:12:48 · 7 answers · asked by Anonymous in Mathematics

We paid not attention to it. Can we focus now?

2007-02-03 17:10:50 · 11 answers · asked by Krish 5 in Weather

2007-02-03 17:10:41 · 26 answers · asked by Anonymous in Mathematics

another science project, need your hypothesis, we are using coke, soapy water lemon juice and bleach, which do you think will clean the penny best?

2007-02-03 17:10:22 · 13 answers · asked by kriscot27 2 in Other - Science

What is the maximum height the ball reaches?

2007-02-03 17:00:51 · 6 answers · asked by dpakx27 1 in Engineering

My son has to make a model for school and I am having a hard time finding ideas. He is in fourth grade, so the simpler the better.Any help would be great, or if you could tell me where to find more info. Thanks!

2007-02-03 16:58:16 · 4 answers · asked by lola 1 in Earth Sciences & Geology

Coffee makers and kettles eventually become clogged with a build up of "scale" from deposits of calcium carbonate and magnesium carbonate.

2007-02-03 16:58:04 · 1 answers · asked by Cutie 4 in Chemistry

2007-02-03 16:57:34 · 4 answers · asked by Rosy 3 in Mathematics

2007-02-03 16:57:07 · 2 answers · asked by Anonymous in Mathematics

if so, do you think that all the meddling we do with nature will effect the spesies down the line? what i mean is, lets say we help a fawn that is born with some major defect (perhaps not being able to stand on its own): do we have to worry about the entire line that comes from that deer suffering the same problem, or will that problem work itself out the very first generation after we release it back into the wild? will the weakness be cut-off because of its weakness, or did we just totally screw all future deer everywhere by introducing a "lame duck" to breed its "handicap" to the others?

2007-02-03 16:56:15 · 2 answers · asked by mr e 4 in Biology

2007-02-03 16:53:50 · 5 answers · asked by Anonymous in Earth Sciences & Geology

except for it's high voltage

2007-02-03 16:53:03 · 6 answers · asked by macgyver 1 in Engineering

2007-02-03 16:52:49 · 5 answers · asked by Anonymous in Mathematics

Acording to the bigbang the universe evolved from a small point which erupted and created the space time contininum at the time of eruption I suppose the point was rotating rapidly because we are all rotating about somethig and this blast nade the matter split up Now imagine this i have made a small ball with a han full of mud and i place it on the ground and rotate it in hthe process of rotation the mud will be splited up from the ball unformly and at last after the ball is all gone i see a disc of mud so my question is why are galaxies in different shapes but not only disc shaped and spiral. I will also be pleased if you would answer for this Why does a body tend to rotate.

2007-02-03 16:51:11 · 6 answers · asked by josyula 2 in Physics

2007-02-03 16:50:35 · 3 answers · asked by Anonymous in Mathematics

I want to know if oral antibiotics use can be traced in a human urine sample by a home or bedside test (NOT some complicated lab procedure). Thanks

2007-02-03 16:50:28 · 6 answers · asked by No_Fins 1 in Medicine