Science & Mathematics - 30 October 2007

What does the absolute value mean and can it ever be a negative number?

2007-10-30 04:38:24 · 6 answers · asked by tuntuni11 1 in Mathematics

circumference is about 25,000 miles

Can someone explain how I can answer this question?

2007-10-30 04:37:19 · 2 answers · asked by >mjd 1 in Earth Sciences & Geology

I have neighbours above and below my flat and every time something, even as small as a pin, drops on the floor upstairs I can hear it in my room with the door shut. Downstairs, there is a boy who likes to shoot a tennis ball at their ceiling( my floor level) but I have never heard the sound of the ball hitting the ceiling. While at the boy's flat one day I noticed that the ball made considarable noise much more than a dropt pin. In my previous flat I always heard noise from upstairs too. Now, back in my room, my head is about the same distance away from the floor as it is from the ceiling. I do not hear the noise from the ball hitting the ceiling downstairs, but that of a dropt pin on the floor upstairs. Does it mean that the noise/sound is heavy so that gravity pulls the sound of the ball downwards and I can therefore not hear it in my room? If this is true why do our cel phone calls go through despite the fact that they have to reach the transmiters against gravity?

2007-10-30 04:36:50 · 5 answers · asked by Sheng Lee 2 in Physics

There are 10 light bulbs in a box.
You need 4 of them.
How many different combinations of 4 light bulbs are possible?

2007-10-30 04:36:34 · 13 answers · asked by Randy C 2 in Mathematics

Suppose you are given three maps, A, B, and C (each 17.5 inches long by 13.5 inches wide). Map A has a scale of 1:62,500; map B a scale of 1:125,000: and a map C a scale of 1:250,000.

Which map represents the greatest area?

Which map represents the smallest ares?


How much area is shown on B compared to that shown on A?

Which map shows the greatest enlargement?

Detail?

I need to understand this!!!!!!!!!!!!!!!!!

* 13 minutes ago
* - 3 days left to answer.

Additional Details

1 second ago
How do I do it?

2007-10-30 04:35:17 · 11 answers · asked by >mjd 1 in Geography

A substance classified as a fluid contains particles that
a. quickly expand into any available space.
b. are held in fixed positions.
c. may slide past each other.
d. are very far from each other.

2007-10-30 04:32:44 · 1 answers · asked by -BrownEyedBeauty- 1 in Physics

How would I "extract" this?

(r+6)^2 = 13

2007-10-30 04:32:06 · 2 answers · asked by Anonymous in Mathematics

For t:R--R,f(X)=e^x- x/e
find the coordinates of the turning point of the graph of y=f(x)


&


State the maximum domain for the function with rule f(x)=2log(e) (x-3)

(The e on the above question 2log(e) is small and below the log)

2007-10-30 04:30:27 · 2 answers · asked by Dom, G 2 in Mathematics

i have glaucoma since i was young, but i take eyedrops (cosopt, lumigan), im a college student now and im afraid if ill loose my eyesight with getting older

2007-10-30 04:30:15 · 2 answers · asked by Anonymous in Medicine

2007-10-30 04:28:27 · 2 answers · asked by Anonymous in Mathematics

2007-10-30 04:27:04 · 3 answers · asked by Anonymous in Chemistry

Define the supremum sup A of abounded
subset A of R......""i will use x-n in sted of x sub n....""
let (x-n)be bounded sequence.define the sequence S-n by S-n = sup{x-n:k>=n} for n belonges to natural numbers "N".prove that the sequence S-n is converge...
i hope that the prove will be in details
thanx

2007-10-30 04:26:15 · 5 answers · asked by Dana S 1 in Mathematics

A student says that the equation (a-9)(a-8)= 20 can be solved as follows : a-9=4 or a-8=5. If this is correct then explain why! I not explain why.How would u advise this student?

2007-10-30 04:24:10 · 8 answers · asked by Anonymous in Mathematics

I am not talking about dreams or things like that, but thiings that go bump in the night or you just knew something.... how could you just explain it away?
My Dad was like that, he had countless experiences but he thought they were coincidence or jsut something that happened. Please tell me about you and your experiences.

2007-10-30 04:21:47 · 7 answers · asked by Kimberlee Ann 5 in Parapsychology

What else produces Gamma rays?

2007-10-30 04:20:02 · 1 answers · asked by spencer 2 in Physics

2007-10-30 04:19:03 · 4 answers · asked by Kimberlee Ann 5 in Parapsychology

i will be greatfully thanks if u answered just make it fast

2007-10-30 04:16:50 · 2 answers · asked by knowledge hunter 1 in Physics

Me and my wife kept karwachauth fast for each other yesterday(29th of Oct07).Unfortunately the moon did not appear uptil midnight and it was the same whole night.Actally it was all cloudy due to cold,so we broke the fast at 11:55 pm.
Was it ok to do that? And also,if we kept this fast on the right date? Please help me finding answer of this questions as my wife is quite worried of not getting a chance to see moon on karwachauth's night.

2007-10-30 04:15:37 · 2 answers · asked by newcum 1 in Astronomy & Space

I already posted this but it wound up in Marriange and Divorce LOL.

2007-10-30 04:13:19 · 10 answers · asked by Kimberlee Ann 5 in Paranormal Phenomena

If evolution always was, then what proof is it that evolution has occured elsewhere. If not why doesn't evolution apply through out the universe?

2007-10-30 04:12:02 · 12 answers · asked by Anonymous in Astronomy & Space

2007-10-30 04:06:25 · 6 answers · asked by tallerballer 1 in Chemistry

I'm curious, what with all the money donated to research for Cancer, Alzheimer's, Diabetes, Parkinson's, Heart Disease, etc., that there only seems to be drug treatment and no total eradicaton. Please prove me wrong.

2007-10-30 04:05:28 · 5 answers · asked by mister_snorkle 1 in Medicine

So first of all look at this img :
http://aycu35.webshots.com/image/31034/2003792274542358389_rs.jpg

OK now as u can see , there are 2 different lenses in the picture one is biconvex and the other one is biconcave . Since u already know that lets get to the point .

Since i am a novice in this catagory , and the teacher promiced to give an A+ to whoever solved this 1st , i beg you to help me find the FOCAL point in both cases .


Thank you all , cheers if u solved it . An img response with a little explaning will do very good .

2007-10-30 04:00:29 · 1 answers · asked by Simon T 2 in Physics

If a car is moving around a circular track in uniform circular motion, with friction present, and a free-body diagram is drawn showing all the forces on the car (3 total forces), then why does the force of the friction, which is parallel to the surface always have a perpendicular or normal force, which is of course perpendicular to the force of friction? I know that there is a force of gravity downward which acts as the opposing force of the earth pushing up on the car, but HOW IS THE FORCE FROM THE TRACK on the car RELATED TO THE FORCE OF FRICTION, AND WHY ARE THE TWO DIFFERENT FORCES PERPENDICULAR. Thanks.

2007-10-30 03:37:41 · 2 answers · asked by M4tr!x 2 in Physics

Is it possible that hot objects repel colder objects and cold
objects are attracted to hot objects ? This may explain how
the planets rotate around the sun and how moons rotate around
planets. When the opposing forces equal out they find their orbit.

2007-10-30 03:34:17 · 4 answers · asked by Ken 1 in Physics

I found out the other day thet the water works near me has over 1000Kg of chlorine stored there and its in a plase surrounded by houses.

Surely that cant be safe can it?

2007-10-30 03:32:15 · 5 answers · asked by lucylonglegs 1 in Chemistry

2007-10-30 03:31:33 · 4 answers · asked by alw0322 1 in Mathematics

2007-10-30 03:31:11 · 4 answers · asked by JL 2 in Biology

2007-10-30 03:27:36 · 5 answers · asked by Anonymous in Chemistry

i don't want to put in a long function every time, i just need to go back and change the variable

2007-10-30 03:27:28 · 3 answers · asked by boroballer 1 in Mathematics