Science & Mathematics - 2 September 2007

2007-09-02 21:01:39 · 7 answers · asked by Sanika N 1 in Astronomy & Space

What is an inverting summer circuit and how does it work?

2007-09-02 20:59:52 · 2 answers · asked by Anonymous in Engineering

Every doubling of sound power,we add 3dB and for every doubling of sound pressure 6dB. In what condition or situation do we double the power and pressure?

2007-09-02 20:59:45 · 2 answers · asked by Silvery_purple 2 in Physics

A space shuttle circles the earth 660 km above the surface in 1 hr 32 min 10 sec. If the average radius of the earth is 6370 km, find the speed of the shuttle in m/s and km/hr.

As I understand it, I need to find the circumference of the earth (C = 2(pi)r). Is the number 660 km redundant?

Thanks.

2007-09-02 20:57:37 · 7 answers · asked by labelapark 6 in Physics

I have seen models of our solor system always portrayed with all the planets on the same plane..... Like a flat dinner plate.
Are the planets really like that or do the different planets in our solar system rotate around the sun at different angles on different planes?
Do the different planets rotate around the sun more like the electrons around the nucleus in the model of an atom, all going in different directions?......or is the solar system flat?
If it is flat, has anyone ever explained why they dont all go around the sun on different planes?
Thanks.

2007-09-02 20:55:14 · 7 answers · asked by perryinjax 3 in Astronomy & Space

2007-09-02 20:53:20 · 17 answers · asked by Anonymous in Geography

ok I said in a few previous articles that light is not the ultimate speed.
You will believe me yet..
About superstrings and light being nothing more than a wave not a particle but a wave.
And all that light is nothing more than vibrations in the superstrings..

http://arxiv.org/abs/0708.0681

2007-09-02 20:51:57 · 12 answers · asked by emc.squared 1 in Physics

I have heard people say there was a conspiracy about the Apollo missions and we never went to the moon. The conspiracy theorists say it was all staged. Why cant anyone produce telescopic photos of the cars and things we left behind on the moon to prove them wrong? Is it too far away?? On the opposite side?? I would assume we have telescopes powerful enough and satelittes etc...
Why have I never seen photos of the artifacts we left behind on the moon taken from Earth? I know they left a car and a flag and some other stuff up there.....Can they be seen from Earth?

2007-09-02 20:46:35 · 4 answers · asked by perryinjax 3 in Astronomy & Space

Is there any way in which a sound could echo infinitely given the right surroundings, for example in a cave system?

2007-09-02 20:34:33 · 6 answers · asked by ceilteach_kitten 2 in Physics

2007-09-02 20:26:28 · 2 answers · asked by niaz_maju.2007 1 in Engineering

I've really being trying to figure this one out, if anyone could help me, I'd very much appreciate it.

If a car travelling at a speed of V can break at an emergency stop at a distance X. Assuming all other conditions are similar if the travelling speed of the car doubles, the stopping speed will be 4x. (I worked that part out)
A driver travelling at 40 km/h in a school zone can break to emergency stop in 3 meters. What would be the breaking distance of the car were travelling at 60 km/h.

Thanks in Advance.

2007-09-02 20:25:41 · 5 answers · asked by fatla00 2 in Physics

Explain the characteristics of an ideal op amp

2007-09-02 20:24:51 · 2 answers · asked by Anonymous in Engineering

Explain the characteristics of an ideal op amp

2007-09-02 20:24:04 · 1 answers · asked by Anonymous in Physics

2007-09-02 20:21:13 · 9 answers · asked by Anonymous in Astronomy & Space

Solve.
A small-business research project estimated that for the years 1998-2003, the total number of retail bicycle stores in a particular region would grow according to the linear equation where x is the number of years after 1998. Graph the equation and use the graph to predict the total number of retail bicycle stores in 2008.

There are a thousand stores

2007-09-02 20:19:49 · 1 answers · asked by Anonymous in Mathematics

I'm Just Bored, lol

2007-09-02 20:19:21 · 11 answers · asked by Thanks 1 in Geography

Explain the operation of an inverting amplifier. What is meant by the gain of the operational amplifier? What is the relationship between inverting amplifier gain and Rf and Rr

2007-09-02 20:17:40 · 1 answers · asked by Anonymous in Physics

2007-09-02 20:01:19 · 8 answers · asked by Paul 1 in Geography

1) lim t-->0 tan(6t) / sin(3t)
2) lim x-->0 (sin^2(4t)) / t^2

I posted this the other day but forgot to specify that we haven't learned L'Hopital's rule yet. So how would I solve these problems otherwise? I'm stuck.

2007-09-02 19:58:50 · 6 answers · asked by Anonymous in Mathematics

Alternatively, what is the average acceleration experienced by the ball to stop it? I think the following formula might need to be rearranged to solve for a.

v^2= v0^2+2ax

v0 = starting velocity
v = ending velocity
a = acceleration
x = distance

I am really bad at rearranging formulas, I managed to get a for acceleration on the left side of the equation as the denominator of v^2, but then I don't know how to get rid of v^2 so a for acceleration is by itself and ready to be solved. Any help would be appreciated.

2007-09-02 19:53:34 · 3 answers · asked by pamphlet_one 2 in Physics

Solve.
A small-business research project estimated that for the years 1998-2003, the total number of retail bicycle stores in a particular region would grow according to the linear equation where x is the number of years after 1998. Graph the equation and use the graph to predict the total number of retail bicycle stores in 2008.

2007-09-02 19:52:26 · 3 answers · asked by Anonymous in Mathematics

Find parametric equations and a parameter interval for the motion of a particle that starts at the point (-2,0) in the xy-plane and traces the circle x^2 + Y^2 = 4 three times clockwise. (There are many ways to do this.)

2007-09-02 19:49:36 · 3 answers · asked by angullgrl91 1 in Mathematics

2007-09-02 19:48:17 · 12 answers · asked by Mr. Smith 5 in Astronomy & Space

2007-09-02 19:44:12 · 3 answers · asked by Anonymous in Astronomy & Space

What is the formula for determining the watts produced by the alternator?

2007-09-02 19:34:38 · 6 answers · asked by pgw1 1 in Engineering

Can anyone tell me what is the Machin's formula for pi.

2007-09-02 19:32:39 · 3 answers · asked by Anonymous in Mathematics

2007-09-02 19:29:23 · 5 answers · asked by nxml81 1 in Chemistry

I am a freshmen at Penn State and I am majoring in engineering. Everybody keeps saying engineering is very difficult. Can anyone tell me exactly the things that make it difficult.

2007-09-02 19:27:12 · 6 answers · asked by Anonymous in Engineering

our running year 2007 can be also be called as AD 2007? does that mean that the years 1587 can ve called as AD 1587? How can the AD system be placed in our calender years?

2007-09-02 19:25:33 · 4 answers · asked by kjijujoseph 1 in Other - Science

Determine whether the equation is a linear equation in two variables.
2y = x - 3

yes
no

2007-09-02 19:22:48 · 6 answers · asked by Anonymous in Mathematics