Science & Mathematics - 3 February 2007

Using the fact that acceleration is the second derivative of position, find the acceleration of the block as a function of time.

Express your answer in terms of w, t, and x(t).

I'm having troubles with many of these types of problems....can anyone help?

2007-02-03 16:49:48 · 1 answers · asked by Anonymous in Physics

2007-02-03 16:48:13 · 9 answers · asked by vexay s 1 in Geography

2007-02-03 16:48:08 · 4 answers · asked by Anonymous in Mathematics

2007-02-03 16:45:23 · 7 answers · asked by Anonymous in Mathematics

is there a difference between percentage error and percentage difference? if so, what is it??

2007-02-03 16:44:39 · 2 answers · asked by What_a_what 2 in Mathematics

2007-02-03 16:40:03 · 3 answers · asked by Anonymous in Mathematics

The problems is:

2x/ x^2+9x+20 times(*) x^2-4x-32/3x^2

SO I MULTIPLIED THE NUMERATORS 2x(x^2-4x-32) AND GOT 2x^3-8x^2-64x, THEN I TOOK OUT A 2x AND GOT 2x(x^2-4x-32)
THEN I FACTORED & GOT 2(x-8)(x+4)

Then I multiplied the denominators and got 3x^4+27x^3+60x^2 THEN I TOOK OUT A 3x^2 AND GOT 3x^2(x^2+9x+20) THEN FACTORED & GOT 3x(x+5)(x+4)

Then the i canceled out the (x+4) {both} AND ENDED WITH
2(X-8) OVER 3X(X+5)

DID I GET IT RIGHT?

-THANK YOU ALL WHO HELPED ME WITH MY OTHER PROBLEMS... I LOVE YOU ALL

2007-02-03 16:37:36 · 6 answers · asked by Becky 1 in Mathematics

First of all, I don't have much electronics experience apart from doing a semester of electronics in yr 12 (and they didn't really teach us how any of it works, just said 'put this resistor here and that there' etc).

I pulled 3 LED's out of a pc which my neighbour was going to throw out, so I don't really know what the voltage range is.. (If that makes it impossible to use them, please tell me which ones to buy because I still want to do the following)
Now, I want to use them in a craft project and I don't have a clue how to hook them up properly. It doesn't really matter to me whether I hook them up to a battery or a power point, but I'm on a low budget so I figure battery would be cheaper, right?

Now, how on earth do I go about making the circuit board for them? Do I need to make a proper circuit board at all (I don't have that liquid for getting the copper off etc)? All I want is for those three LED's to be lit up solid.

2007-02-03 16:35:49 · 3 answers · asked by Pietzki 3 in Physics

2007-02-03 16:34:36 · 9 answers · asked by ellen105 2 in Chemistry

http://www.ipcc.ch/pub/online.htm

2007-02-03 16:33:43 · 2 answers · asked by rostov 5 in Biology

I think it is a unit of measurement.

2007-02-03 16:33:05 · 1 answers · asked by marie2dessy 3 in Engineering

A computing center has 3 processors that receive n jobs, with the jobs assigned
to the processors purely at random so that all of the 3n possible assignments
are equally likely. Find the probability that exactly one processor has no jobs.

2007-02-03 16:31:55 · 2 answers · asked by Trivi 3 in Mathematics

Compared with Hardy-Weinberg predictions, populations that have practiced assortative mating have

A) fewer homozygotes
B) more homozygotes
C) more mutations
D) more heterozygotes
E) less natural selection .

2007-02-03 16:26:58 · 3 answers · asked by ph103 1 in Biology

Albert Einstein used only about 10% of his mental capacity throughout his lifetime. Why is it that we cannot tap the other 90%? We can teach stroke victims to learn how to function again but are they only regaining what they have lost or are they tapping into what they have not already used?

2007-02-03 16:24:52 · 14 answers · asked by jmichaelr2377 1 in Biology

2007-02-03 16:20:30 · 4 answers · asked by Michael J 1 in Biology

If time goes on for billions of years more, and space has trillions of stars that could support habitable planets, the probablility of discovering time travel at some point in the future goes up. It would seem like we should be seeing thousands of visitors from the future given these odds. Maybe this means there is no future.

2007-02-03 16:17:12 · 9 answers · asked by Zefram 2 in Physics

2007-02-03 16:17:01 · 1 answers · asked by Anonymous in Earth Sciences & Geology

2007-02-03 16:15:55 · 11 answers · asked by suryakantam 1 in Earth Sciences & Geology

write the slope intercept form of the equation of the line through the given point- parallel to the given line and perpendicular to the given line.

point 4,-2 line y=1 Thank you if you can help!

2007-02-03 16:13:33 · 2 answers · asked by Boo Radley 4 in Mathematics

I propose this as a great way to dispose of annoying pests - would he be a good replacement for uranium ?

2007-02-03 16:12:44 · 4 answers · asked by Angela 2 in Physics

2007-02-03 16:11:58 · 1 answers · asked by ke k 1 in Chemistry

Please, no stupid God answers.

2007-02-03 16:11:42 · 19 answers · asked by Anonymous in Astronomy & Space

I'm in 2nd semester general chemistry, and while I understood the majority of the topics we covered in 1st semester, acids and bases are killing me!

1. Am I missing something obvious, or is the topic just inherently hard?

2. Any recommendations for websites that I could try to learn from? I need to start from the very basics.

Example of a problem I can't do:

Calculate the pH of a buffer solution made by mixing 25.00 mL of 0.2 M sodium acetate and 25.00 mL of 0.1 M HCl.

2007-02-03 16:07:46 · 2 answers · asked by Cat H 1 in Chemistry

Why is it that the planet Mars has no magnetic field, even with an iron core much like the Earth's?

2007-02-03 16:07:24 · 7 answers · asked by Dacey 1 in Astronomy & Space

it is based on gravitation?

2007-02-03 16:06:30 · 3 answers · asked by Anonymous in Physics

2007-02-03 16:05:47 · 9 answers · asked by Suresh 1 in Physics

2007-02-03 16:05:30 · 2 answers · asked by RAFAEL G 1 in Engineering

The evidence seems overwhelming. They say that a panel of 25 scientists are 90% confident that GW is to blame on humans. However, we must look between the lines. It is standard in studies to use a 95% confidence interval, this study uses a 90% CI. This shows that this study is not credible. What most likely happened is they used a 95% CI, the data was not statistacally significant, and they did not get their desired outcome. Therefore they could not conclude that global warming is man made. If they decreased the CI, it is then likely they employed other methods such as eliminating unwanted data, or substituting data, in order to get the desired results. It would be OK to use a 90% CI if the results at 95% CI are also published. It is common practice, though, to use only a 95%CI. Also, the panel of scientists were politically appointed, so it is likely they have a political agenda. Global warming may very well be man made, but this study does not concur with that hypothesis.

2007-02-03 16:05:19 · 6 answers · asked by TE 5 in Earth Sciences & Geology

I am not a math person. I want to combine the chance of something happening with these four numbers. 38%,33%,60%,36%
what is the chance of at least one of those things occurring?

2007-02-03 16:05:01 · 3 answers · asked by insenid 1 in Mathematics

will it destroy us and our earth??

2007-02-03 16:04:49 · 16 answers · asked by Anonymous in Weather