Science & Mathematics - 1 February 2007

(2/x^2)-sqrt(4), what is this when you use the defenition of derivative. I cant get it simplified all the way down.

2007-02-01 15:15:46 · 7 answers · asked by Chris 1 in Mathematics

i want to buy a dress that costs $75.
but I dont have any money.
so i borrow $25 from 3 frens.
and then 25 x 3 = 75.
that will make up $75.

I enter the shop to buy the dress.
but the shop owner says $70 is enough.
so the shop owner handed me the dress and also return me the extra $5.

okay now with the $5, i return each of my fren $1.
after returning each of them $1, im only left with $2 right. (5 - 3 = 2)
then since i return 3 of them $1, that means i still owe each of them $24.

now 24 x 3 = 72
plus the extra $2 left, i only have $74.
so where did the $1 go??
it is supposed to be $75

Think think think.. =]

2007-02-01 15:15:22 · 6 answers · asked by glamourliciouss 1 in Mathematics

What is a great circle?

2007-02-01 15:13:46 · 7 answers · asked by Anonymous in Geography

Here's a question from my AP Chemistry homework that is stumping me:

What would the mole fraction of toluene be in a solution for
which the partial pressure of benzene equaled that of
toluene? Assume only toluene and benzene vapor is present.

(Benzene: d = .8765 g/ml; Pvap = 384 torr (60 C); FW = 78.12 g/mol)
(Toluene: d = .8669 g/ml; Pvap = 133 torr (60 C); FW = 92.15 g/mol)


If you would, could you please explain your answer or show work? Thank you so much.

2007-02-01 15:13:41 · 2 answers · asked by eyanyo13 3 in Chemistry

Give real-life examples of both arithmetic and geometric sequences and series. Explain how these examples might affect you personally.

2007-02-01 15:13:23 · 2 answers · asked by ash 2 in Mathematics

1.Which 1of the following appliance part gets the hardest service? A.Switch B.Thermostat C.Heating Element D.Line Cord
2. The color used for the hot side of house wiring is?
A.Green B.White C.Gray D.Black
3.AWG No.16 linecord with type HPN insulation has an ampacity? A.12amp B.13amp C.15amp D.17amp
4.To heat a room quickly, some electric room heaters R provided with? A.heavy metal case B.motor-driven fan C.pushbutton switch D.automatic thermostat.
5.If the current flowing through an electric heater increases from 6-12 amp while the voltage remains the same, the heat produced by the heater will b? A.reduced 1half B.unchanged C.2X'sthe original heat D.4X's the original heat.
6.The wires used in a heating element are usually made of?
A.Copper B.Steel C.Aluminum D.Nichrome.
7.Why does a thermostat blade bend when heated or cooled?
A.Made of 2different materials B.difference in temp. between the blade ends C.diff. currents are applied @ the ends?

2007-02-01 15:12:19 · 3 answers · asked by jennie m 1 in Engineering

Gauss's Law

a flat circle of radius 18 cm is placed in a uniform electric field of magnitude 5.8 x 10^2 N/C. What is the electric flux through the circle when its face is (a) perpendicular to the field lines (b) at 45 degrees to the field lines, and (c) parallel to the field lines?

Please provide step-by-step work if possible. Thank you!

2007-02-01 15:09:34 · 1 answers · asked by Sparkles 3 in Physics

What do you think will happen if for some reason humans were able to bring the recently (about 500 years or so) extinct animals back to life? Do you think that they sould do it? Why or why not.

2007-02-01 15:09:16 · 6 answers · asked by Becca 2 in Other - Science

I've always wondered really.

2007-02-01 15:09:11 · 4 answers · asked by Diba 2 in Zoology

from algebra 2

2007-02-01 15:09:08 · 8 answers · asked by carmal 1 in Mathematics

It was in the news that earrings and other jewelry from Claire's and other brands decrease your IQ. How can lead do something like this? How is it even possible? How would I know which earrings are composed of lead and which aren't?

2007-02-01 15:08:54 · 7 answers · asked by m&ms 1 in Other - Science

http://img240.imageshack.us/img240/9383/downloadvz1.jpg

This was allegedly caught from a river in Johor, Malaysia.

2007-02-01 15:08:06 · 3 answers · asked by xcy 1 in Zoology

Thanks in advance!

2007-02-01 15:08:00 · 1 answers · asked by frogster99 2 in Chemistry

I understand that paroxetine is a phenylpiperidine SSRI but I'd like to know what a phenylpiperidine is and it's mechanism of action.

2007-02-01 15:07:54 · 1 answers · asked by ? 2 in Medicine

I really need help on this.
And could you explain how you got your answer to me.
THANKS!!!

2007-02-01 15:07:48 · 10 answers · asked by jorie715 2 in Mathematics

Considering the effect of gravity does that mean you would stop in the middle?

2007-02-01 15:07:03 · 20 answers · asked by Anonymous in Physics

2007-02-01 15:05:27 · 11 answers · asked by Lou 2 in Mathematics

2007-02-01 15:04:43 · 7 answers · asked by Anonymous in Chemistry

2007-02-01 15:03:31 · 11 answers · asked by Lou 2 in Mathematics

A house with a 18.1 × 103 ft2 floor area and 9.00 ft high ceilings is to be heated with propane. How many kilograms of propane would be needed to raise the temperature of the air inside the house from 59.0 oF to
74.0 oF ?. In this calculation your are ignoring the temperature of the walls etc.


The moloar specific heat of the air inside the house is 30.2 J mol −1 oC −1
The average density of air over this temperature range can be estimated to be 1.22 g/L.
The molar mass of air is 29.1 g/mol.
There are 28.317 liters in a cubic foot.
The molar heat of combustion of propane is −2220.047 kJ/mol

2007-02-01 15:02:43 · 1 answers · asked by nietzsche 1 in Chemistry

A compound with the formula C2H6O2 has a boiling point of 198 C. From the data below, deduce its Lewis structure.

CH4 -182 C
CH3CH3 -89 C
CH3CH2CH3 -42 C
CH3OH 65 C
CH3CH2OH 78.5 C
CH3CH2CH2OH 97 C
CH3CH2OCH2CH3 34.5 C

2007-02-01 15:02:43 · 1 answers · asked by pa0250 1 in Chemistry

your high point is at (5,-2)
your low point is at (21,-7)
write an equation using y=a Sin b (t-h)+k

2007-02-01 15:02:33 · 1 answers · asked by cje828 1 in Mathematics

2007-02-01 15:01:48 · 12 answers · asked by Breanna S 1 in Chemistry

A compound with the formula C2H6O2 has a boiling point of 198 C. From the data below, deduce its Lewis structure.

CH4 -182 C
CH3CH3 -89 C
CH3CH2CH3 -42 C
CH3OH 65 C
CH3CH2OH 78.5 C
CH3CH2CH2OH 97 C
CH3CH2OCH2CH3 34.5 C

2007-02-01 15:01:22 · 2 answers · asked by pa0250 1 in Mathematics

From which year should I start counting leap years and where do I stop counting? I tried from 4AD to 2004. A leap year has 53 tuesdays only if starts on Mon or Tue. Accordingly, it gives me 137/500. Ans is 2/7. Wondering where am I going wrong?

2007-02-01 14:59:22 · 7 answers · asked by Mau 3 in Mathematics

2007-02-01 14:58:48 · 5 answers · asked by Anonymous in Zoology

the spots in Australia are- South Aust, Vic & N.S.W. -- Northern Territory, Qld & N.S.W.--South Aust, West Aust & Northern Territory

2007-02-01 14:57:18 · 1 answers · asked by curious1 2 in Geography

An unknown compound with molecular formula C9H18O3 shows only one signal in its proton nmr spectrum.In the IR spectrum a strong band is seen near 1300cm^-1. propose a structure for this compound.. what do i do and where do i start from........ ???????????????

2007-02-01 14:56:43 · 3 answers · asked by ME 1 in Chemistry

1.(x+4)(x-3)=0

2.x^2+6x+9=0

3. y=6-x
y=-4x+3

4. Y=5-3x
3x+2y=8

2007-02-01 14:55:32 · 1 answers · asked by User84 4 in Mathematics

20) y/2 - 2 > 10

30) 3t - 13 < 5t

15)1/3b - 2 > 5

24) -1/2x + 3 > 4

help!!

2007-02-01 14:53:02 · 2 answers · asked by 123 1 in Mathematics