Science & Mathematics - 20 September 2007

volcanic or seimic. is it near any huge volcanoes or fault lines?


THANKYOU !!!
xoxox

2007-09-20 17:42:06 · 1 answers · asked by ? 4 in Earth Sciences & Geology

Numeric Response:
Use a system of equations to solve a problem involving coins.

Ryan has $21.40 in dimes and quarters. He has 103 coins in all. How many of each type of coin does he have?

2007-09-20 17:40:08 · 7 answers · asked by Anonymous in Mathematics

We did a lab on pennies post-1982 and pre-1982.

Pre-1982: contain 95% copper, 5% zinc.
Post-1982: purpose of this lab is to determine this.

We added hydrochloric acid solution. After 1 day, there were bubbles coming out from the notches that we carved in. After 2 days, the pennies turned a little black and the pre-1982 penny was harder than the post-1982 penny.

Questions:
Why did the pennies turn a little black?
What can you conclude about the two different metals and their reactivity with strong acids?
Would this have practical/consumer applications?

By the way, I really don't get this lab. Can someone also explain what's the point of this lab?

2007-09-20 17:35:55 · 8 answers · asked by IN0C3NT 2 in Chemistry

just wondering..when mosquitos(or any other flying animal) fly, is it true that they are exerting a force downwards(by flapping their wings),thus by newton's third law there'll be a reaction force(lift) which pushes them up.

if that is true, why mosquitos dont exist on higher altitudes?is it because of the force needed to push them is too much?or is it something to deal with pressure difference??

please answer using physics concepts,thank you.

2007-09-20 17:35:13 · 5 answers · asked by edta 2 in Physics

i know how to find the mass(overflow can) but i need to know how to find the volume so i can divide the too to get mass(d=m/v)do you just read the marking on the graduated cylinder AFTER you have found the mass of the object? please help, thanks in advance!

2007-09-20 17:34:07 · 3 answers · asked by lions48 2 in Physics

2007-09-20 17:34:02 · 6 answers · asked by Anonymous in Mathematics

The direction says "Find the equation of the line described in slope-intercept form" The question is: Has an x-intercept of 5 and a y-intercept of -3. I know where the -3 belongs but I don't know where to plug in the -5. Please explain :]
Thanks

2007-09-20 17:33:43 · 6 answers · asked by Anonymous in Mathematics

A friend is waiting to see if anyone can come up with a solution..
Thx

2007-09-20 17:32:00 · 4 answers · asked by Steve 7 in Mathematics

2007-09-20 17:24:31 · 1 answers · asked by yodno49 1 in Chemistry

A square will tessellate a plane; can we always find a square that will tessellate a rectangle?

2007-09-20 17:24:11 · 5 answers · asked by Anonymous in Mathematics

2007-09-20 17:22:43 · 9 answers · asked by Anonymous in Astronomy & Space

Determine all values of the constant "a" such that the following function is continuous for all real numbers.

http://img525.imageshack.us/img525/526/mathxq4.png

i dont have the faintist idea on how to do this

2007-09-20 17:22:21 · 4 answers · asked by adr k 2 in Mathematics

Personally, I don't. There are several factors that contribute to the way our planet is and the life that exists on it. First of all the relative size of the Sun, Moon and Earth. The Earth has a moon that is 1/4 its own size and that effects the amount of gravity pulling on the Earth. Also, we're a nice distance away from the sun, not too close to burn up our atmosphere and not so far away that the heat from the sun can't give us proper lighting and the right amount of heat and all those nutrients we get from the sun. And, wow, there's so many more things that would just make it impossible for there to be another planet just like Earth. I could go on forever!

2007-09-20 17:18:03 · 14 answers · asked by shannon d 1 in Astronomy & Space

2007-09-20 17:16:46 · 4 answers · asked by Sa 1 in Other - Science

Is there anyone out there who knows anything about biostatistics. I have a homework assignment due Monday & I have no clue how to solve one of the problems. Here's what the paper says,

2007-09-20 17:14:17 · 3 answers · asked by little_ash_2003 3 in Mathematics

2007-09-20 17:14:00 · 4 answers · asked by Anonymous in Mathematics

2007-09-20 17:10:24 · 3 answers · asked by your_ma_was_here 1 in Medicine

can someone explain this to me?

2007-09-20 17:10:12 · 8 answers · asked by jorie715 2 in Mathematics

Not too sure on calculating average velocity, here is a question

if a ball is thrown into the air with a velocity of 40ft/s its height in feet t seconds later is given by y=40t-16t^2

find the average velocity for the time period beginning when t=2 and lasting

a) .5 sec
b) .1 sec

2007-09-20 17:08:30 · 3 answers · asked by burgler09 5 in Mathematics

Obviously rough estimates... or anybody got a good link?

2007-09-20 17:07:38 · 12 answers · asked by CJ 3 in Astronomy & Space

Find the first three terms in the expansion of

(i) (3 + x) ^5

Please show your workings clearly. Thank you. =)

2007-09-20 17:05:47 · 4 answers · asked by Anonymous in Mathematics

2007-09-20 17:05:00 · 10 answers · asked by s b 1 in Medicine

2007-09-20 17:04:30 · 4 answers · asked by Thunder Clap 1 in Weather

A jet plane traveling horizontally at 150ms^-1 drops a rocket from a very tall height. The rocket immediately fires its engines after it is released from the plane, causing a 10.0ms^-2 (acceleration) in the X-DIRECTION (no x=vt), while falling under the influence of gravity in the y-direction. After the rocket has fallen 250 m, find:

a) the velocity in the y-direction
b) the velocity in the x-direction
c) the magnitute and direction of its velocity
d) how far it has traveled horizontally.

Neglect lift & drag forces.

THANKS!!! :)

(work is also appreciated)

2007-09-20 16:59:51 · 3 answers · asked by bluenecklace 2 in Physics

2007-09-20 16:57:42 · 2 answers · asked by Anonymous in Mathematics

1. 1/7 (x-3) =1/8 (x-2)

2. 1/4 (x-7)= 1/5 (x-8)

3.-(6x+5) - (9x-7) =11 - (5x+1)

2007-09-20 16:57:04 · 6 answers · asked by GO Saints!! 3 in Mathematics

between my finger and the LCD of my computer is infinity space but i can still reach the LCD screen And touch it
how is this possible

2007-09-20 16:55:33 · 6 answers · asked by Mehran.S 4 in Physics

So I am looking at a site that sells magnets.
Some say:
Pulling Force: 28.67 lbs
and some say
Holding power is 24.8 lbs.

what is the difference between pulling and holding?

2007-09-20 16:51:41 · 2 answers · asked by Philip Augustus 3 in Engineering

Three times 1/3 equals one. 1/3 represented as a decimal is .333333333 etc. So does .99 equal 1?

2007-09-20 16:51:05 · 11 answers · asked by Archimedes 1 in Mathematics

A professional race-car driver buys a car that can accelerate at 69.0 m/s2. The racer decides to race against another driver in a souped-up stock car. Both start from rest, but the stock-car driver leaves 1.0 s before the driver of the sports car. The stock car moves with a constant acceleration of 34.0 m/s2.

A)Find the time it takes the sports-car driver to overtake the stock-car driver.
B)Find the distance the two drivers travel before they are side by side.
C)Find the velocities of both cars at the instant they are side by side.
(Both Race Car and Stock Car.)
Thank you [:

2007-09-20 16:50:21 · 1 answers · asked by Anonymous in Physics