Science & Mathematics - 21 October 2007

Why is it useful?

2007-10-21 20:30:39 · 4 answers · asked by Tland 3 in Astronomy & Space

an elevator is descending at a constant speed.a passenger drops a coin to the floor.what accleration would (1)the passenger and(2)a person at rest with respect to the elevator shaft observe for the falling coin?

2007-10-21 20:30:03 · 3 answers · asked by aryan e 1 in Engineering

geography question

2007-10-21 20:29:01 · 2 answers · asked by Anonymous in Geography

for example; how do i find the derevative of f(3) from a given graph ?

2007-10-21 20:28:37 · 2 answers · asked by Warrior of the Light 3 in Mathematics

I am using a 2n3055 NPN transistor as a switch gate. The base is supplied via a signal gnerator. One moment, it was working fine and then... all went silent. How can I tell if it is the fault of the transistor?

2007-10-21 20:23:26 · 7 answers · asked by Tango 1 in Engineering

Is this possible according to the laws of physics, and if I did manage to do it, would it be a worthwhile invention, with potential?

Ok, so we have a little machine completely enclosed in a box, and the whole thing is on wheels. This machine has no external moving parts and does not need to interact with anything outside its enclosure to operate. This vehicle(since it's on wheels) can also propel itself about as fast as a turtle.

Is this possible, and is it something useful?

2007-10-21 20:22:34 · 7 answers · asked by worried person 1 in Engineering

X=age
Y=income or the equation ( -49x^2+4,606x-52,000)

(^2) means square root or -49x squared (I hope that makes sense)

But if Y= 42080.00

What is X

please help me I'm really stumped.

2007-10-21 20:19:22 · 5 answers · asked by Anonymous in Mathematics

What's the mirror manufacturing process and what's the name of the machine that makes the 'surface' of a mirror shiny and reflective?

2007-10-21 20:17:40 · 3 answers · asked by ziggy 2 in Engineering

What are we doing on this Planet, and why it is going around and around and around...???

2007-10-21 20:17:13 · 12 answers · asked by ALEXANDER 2 in Astronomy & Space

if a charged +Q and -Q on the plates of a capacitor are constant,what happens to the potential difference between plates when the plates are moved closer together?

2007-10-21 20:10:57 · 2 answers · asked by wizard21 1 in Physics

Since they do not use mitochondria and the electron transport chain to harvest ATP, but rather obtain it from photosynthesis

2007-10-21 20:10:48 · 5 answers · asked by Dead Birds Don't Poop 5 in Biology

problem 1

the product of two consecutive positive integers is 55 more than their sum. find the integers

problem 2

if 6 is added to the square of a number, the result is 22. find all such numbers.

problem 3

the product of the page numbers on two facing pages of a book is 600. find the page numbers

2007-10-21 20:06:58 · 8 answers · asked by David 1 in Mathematics

My mom passed last July 06 and I think about her every day and just miss her so much. Alot of people that have lost loved ones say they feel their presence around or see signs that they are around, or have dreams. I haven't had any of this happen, I don't just sit around and dwell on it every day, I have children to take care of. I just miss her so much, is there anything I can say or do to feel my mom's presence around.

Sorry if this sounds odd to some, I guess it is easier to ask strangers these questions than people you know.

2007-10-21 20:05:04 · 23 answers · asked by Lucy 5 in Paranormal Phenomena

it is possible to connect several resistors with different resistances so that they all have the same potential difference? if so, will the current be the same through all resistors?

2007-10-21 20:03:50 · 3 answers · asked by wizard21 1 in Engineering

The first order decay of a radionuclide was observed. The initial activity was 0.00658 disintegrations per second per gram and after 317 seconds, the activity was 0.00213 disintegrations per second per gram. What is the half-life, in seconds, of the radionuclide?

2007-10-21 20:00:06 · 1 answers · asked by Anonymous in Chemistry

Is there a reason?I ask because well known psychic Sylvia Browne said it.I checked the Obits and it's correct.What's going on?

2007-10-21 19:51:44 · 18 answers · asked by Dr. NG 7 in Paranormal Phenomena

Most science fiction ends up becoming reality sooner or later, except there's a difference between a flying car and an ancient alien civilization. I wonder, is there a group that maybe some people know about and others don't? Some kind of MIB....

What are some good sites to learn about such "conspiracy theories", or about any of the mythology of such creatures, shared by many groups and cultures?

2007-10-21 19:42:34 · 11 answers · asked by denimcap 4 in Other - Alternative

2007-10-21 19:33:43 · 3 answers · asked by kr 1 in Botany

1. Assume that the radius r of a sphere is expanding at a rate of 14in./min. It's surface area is 4π r^2. Determine the rate at which the surface area is changing with respect to time at t=2min, assuming that r=3 at t=0

2.At a given moment, a plane passes directly above a radar station at an altitude of 6 miles. (after drawing a diagram) Suppose that the line through the radar station and the plane makes an angle θ with the horizontal. How fast is θ changing 10 min after the plane passes over the radar station?

2007-10-21 19:27:55 · 2 answers · asked by Anny P 1 in Mathematics

the height at which it is dropped must be equal to 2.7 times the radius of the loop... from where is this 2.7 derived?

2007-10-21 19:14:40 · 3 answers · asked by Robert 1 in Physics

If P(x) = 2x^3 - ax^2 + 10 and P(-2) = 4, find P(3).

What is the value of a?
What is the value of P(3)?

2007-10-21 19:09:50 · 9 answers · asked by Anonymous in Mathematics

2007-10-21 19:09:40 · 6 answers · asked by Anonymous in Mathematics

If the polynomial kx^3 – 15x^2 + 27x – 5k is divisible by x – 2, the value of k is

A) 3
B) 2
C) -3
D) -2

2007-10-21 19:07:58 · 4 answers · asked by Anonymous in Mathematics

Use the remainder theorem to find the remainder when 2x^3 - 1x^2 + 9x - 25 is divided by x + 4.

2007-10-21 19:05:35 · 5 answers · asked by Anonymous in Mathematics

I asked this a minute ago (all answered instantly) but I'm reading a book on Feynman and I'll quote: Time delay had not been a feature of the original electromagnetic theory. In Maxwell's time, on the eve of relativity, it still seemed natural to assume, as Newton had, that forces acted instantaneously. An imaginative leap was needed to see that the earth swerves in its orbit not because the sun is there but because it was there eight minutes before, the time needed for gravity's influence to cross nearly a hundred million miles of space--to see that if the sun were plucked away, the earth would continue to orbit for eight minutes.
From Genius ~ Richard Feynman and Modern Physics.
The text is from the 1940's. Is this relativity? Is it the current theory?

2007-10-21 19:05:07 · 9 answers · asked by Anonymous in Physics

1783814567

2007-10-21 18:57:02 · 19 answers · asked by David 1 in Mathematics

2007-10-21 18:56:20 · 6 answers · asked by Anonymous in Astronomy & Space

Vertical displacement?

2007-10-21 18:48:42 · 2 answers · asked by Lightning 1 in Mathematics

i just wont to know-1 word answer(yes or no)with an explaination!!!!!
i hate people who say "maybe.its ur opinion"

2007-10-21 18:40:16 · 4 answers · asked by Anonymous in Astronomy & Space

How do you picture an alien?

2007-10-21 18:39:46 · 6 answers · asked by Anonymous in Astronomy & Space