Science & Mathematics - 22 October 2007

find the solution y(t) for
y'' - 2y' + 7y = sin(t) y(0)= 0 y'(0) = 0

I was able to reach the laplace transform of y(t) as:
1/ (s^2 + 1) ( s^2 - 2s + 7)

but i have no idea how to invert it back into y(t), please help me

2007-10-22 19:55:02 · 5 answers · asked by phil h 2 in Mathematics

I used to be able to do logorithims a long while ago, but now I forgot how to. I think I got the hang of it now, but I just want to make sure.

2007-10-22 19:52:00 · 7 answers · asked by Conservative Jesus 1 in Mathematics

1. The area of a gymnasium floor is 264 square yards. The floor is 11 yards wide. How long is the floor?
A.253 yards
B.24 yards
C.11 yards
D.242 yards

2.The area of a square piece of cardboard is 81 sq.in. What is the length of the cardboard?
A.6.28in
B.3.14in
C.8in
D.9in

3.How much water can be held by a cylindrical tank with a radius of 12 feet and a height of 30 feet?
A.13,564.8 cubic feet
B.2,260.8 cubic feet
C.33,912 cubic feet
D.54,259.20 cubic feet

2007-10-22 19:50:45 · 7 answers · asked by BravesFanForLife 3 in Mathematics

The volume, V(w) of a garden shed can be represented by the expression V(w) = w^3 - 10w^2 + 31w - 30, where w is the width of the garden shed in metres. Completely factor the expression. Find the dimensions of the garden shed.

2007-10-22 19:44:11 · 2 answers · asked by Anonymous in Mathematics

2007-10-22 19:42:24 · 2 answers · asked by Anonymous in Mathematics

2007-10-22 19:41:45 · 2 answers · asked by candy noel 1 in Astronomy & Space

If P(-2/3) = 0, then one factor of the polynomial P(x) must be

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

2007-10-22 19:41:21 · 5 answers · asked by Anonymous in Mathematics

GTG CAC CTG ACT CCT GAG GAG

2007-10-22 19:38:16 · 7 answers · asked by renee 2 in Biology

If A and B are 8 x2 matrices, and C is a 5 x 8 matrix, which of the following are defined?

A. B–A
B. AC
C. C transpose
D. BA transpose
E. CB
F. C+A

2007-10-22 19:37:09 · 3 answers · asked by Anonymous in Mathematics

what is the GCF?

2007-10-22 19:34:47 · 4 answers · asked by mig_e72 1 in Mathematics

Can you tell me what my grandmas name is and if she wants to say somethingto me and my family

2007-10-22 19:34:08 · 6 answers · asked by Proud Mommy of Caiden Thomas 07/20/12 5 in Paranormal Phenomena

Find the value for k for which the matrix
A=
-3 -6 -18
2 -9 -14
-8 3 k
has rank 2.
K=

2007-10-22 19:32:09 · 2 answers · asked by Anonymous in Mathematics

Can someone tell me how to use geological maps to determine wether there has been a gain or loss of ground.

2007-10-22 19:30:52 · 2 answers · asked by Anonymous in Earth Sciences & Geology

----------
T U
(There are dots at each end of the line segment)
->
TU
<-->
UT
<-->
TU
----
TU

2007-10-22 19:25:29 · 2 answers · asked by BravesFanForLife 3 in Mathematics

2007-10-22 19:20:43 · 3 answers · asked by Anonymous in Mathematics

2007-10-22 19:13:54 · 6 answers · asked by pramod n 1 in Other - Science

whoever gives me both of them they will get best answer

2007-10-22 19:09:52 · 6 answers · asked by Too CooL 3 in Geography

I just don't really understand the concept of e fully.

2007-10-22 19:09:30 · 10 answers · asked by Conservative Jesus 1 in Mathematics

Ok tonight I was taking pictures of my neice and dog, when I started noticing bubbles in them, then my mom had to tell me that that's what spirits look like, so I did some research online after she left and saw that this was true, I have some pics and could someone tell me what it is! It's kind of creeping me out!

This is three pics of a chair, one taken right after the other at the same angle, and notice on the 2nd one that there are hardly any in it.
http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6011.jpg

http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6017.jpg

http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6016-1.jpg

Here are some more with weird bubbles
http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6013.jpg

http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6009-1.jpg

http://i217.photobucket.com/albums/cc288/KistyJo/Pictures6006.jpg

2007-10-22 19:05:08 · 19 answers · asked by Brecken's Mommy 3 in Paranormal Phenomena

when trying to find C,
why is it possible that there are two answers

2007-10-22 19:04:59 · 6 answers · asked by Anonymous in Mathematics

1.188.4 centimeters
2.47.1 centimeters
3.94.2 centimeters
4.9.55 centimeters

2007-10-22 19:04:19 · 10 answers · asked by BravesFanForLife 3 in Mathematics

(x^2-1)^2(x+1)^(1/2)/(x-1)^-(3/2)

The answer is apparently "very easy", with "no tricks" breaking down to a much simpler form with an x^7 somewhere in it. Its been driving me barmy for weeks, as even the on-line calculators blow up trying to reach the answer..I've tried looking for diff's of squares,tried squaring the lot, square rooting it all, but with no denominator it just inflates and complicates

2007-10-22 18:51:31 · 2 answers · asked by c0cky 5 in Mathematics

3.364g of hydrated barium chloride BaCl2 xH20 was dissolved in water and made up to a total volume of 250ml . 10ml of this solution required 46.92ml of 2.530 x 10^-2 M silver nitrate for compelte reaction. Calculate the value of x in the formula of hydrated barium chloride, given the net ionic equation for precipitation below
5Fe + MnO4 + 8H ---> 5Fe + Mn + 4H2O

2007-10-22 18:49:10 · 2 answers · asked by techie08 2 in Chemistry

i m not referring to the rumoured one haunting s.carolina swamps

2007-10-22 18:46:57 · 6 answers · asked by Khool 2 in Paranormal Phenomena

2007-10-22 18:43:31 · 3 answers · asked by Anonymous in Mathematics

Write the following polynomial in terms of its linear factors:

P(x)=x^4-5x^3+2x^2+22x-22


So far I have used synthetic division and found that there are two zeros and the upper boundry is 5 while the lower is -2. I honestly am not even sure if I am even on the right path. Can someone please help me?

Thank you!

2007-10-22 18:40:38 · 3 answers · asked by Doodlebug 4 in Mathematics

There are many theories, models, and controversies about the physics of black holes, the 'internal' structure where the laws of physics break down. I've thought about this subject since I first learned of black holes in middle school, then, some time ago, I read an article on space.com about 'quark' stars. Going by observational evidence of the properties possesed by suspected black holes, I came up with the following structure : Imagine if you will a star, let's say 10 solar masses, that has exploded as a supernova while the remains collapse inward. Since the mass is too great to form a white dwarf or even a neutron star, some other more radical transformation of the remaining matter must take place. Since we theorize that remains up to 3 solar masses form neutron stars due to the fact that neutrons could normally not be compressed any further, then perhaps these remains briefly pass through a stage of being a neutron star until the sheer mass overcomes the incompressibility of the neutrons and causes them to split into their component quarks. By this time, escape velocity exceeds the speed of light, and an 'event horizon' has formed around a seething mass of free quarks. As matter gets drawn into the gravitational well this has created, it too gets compressed into component quarks while still adding mass to the whole. Meanwhile, within this 'quark soup', some of the quarks recombine to form sub-atomic particles and are just as quickly broken down again, however, some of these newly forged particles manage to get trapped in the intense magnetic field lines and are able to escape through the magnetic poles. Such a mechnism of sub-atomic particle breakdown, combined with new particles being generated and shot out of the poles could also obey the Law of the Conservation of Energy, while avoiding the infinite density problem common to traditional models. Unfortunately, I'm not a knowledgeable enough mathmetician to calculate the details, but the outline makes for a worthwile idea.

2007-10-22 18:38:09 · 5 answers · asked by Anonymous in Astronomy & Space

Astronauts do and Astronomers watch so do Astronomers take offence to being called voyeur's?

2007-10-22 18:38:06 · 8 answers · asked by Anonymous in Astronomy & Space

2007-10-22 18:37:59 · 2 answers · asked by deepak_8584 1 in Engineering

Teacher said 4 isn't used in the problem. Please help, although she lies so try it....

2007-10-22 18:32:13 · 4 answers · asked by Joab C 2 in Mathematics