Science & Mathematics - 24 September 2007

if anyone knows the mothod of finding the answer to this question i would really apreciate it

4
---

3-/7

its rationalising the denominator

i was doing well up to now

much apriciated

best comment for som1 that tells me the method too!!!

cheers!

2007-09-24 06:34:12 · 2 answers · asked by Dom est.1990 2 in Mathematics

THere are 2 cities 4050 apart. A plane leaves one of them, traveling towards the other at 400 miles per hour. At the same time a plane leaves the other city, traveling at an average speed of 410 miles per hour. How long will it take them to meet?

2007-09-24 06:33:54 · 4 answers · asked by higherlovetx 5 in Mathematics

The density of gold is 19.32 g/cm^3. And ingot of gold measures 15 x 7.5 x 2.0 cm. How many gold atoms are in the ingot? Is the answer 1.33 x 10^25 atoms (with correct significant figures)?

2007-09-24 06:33:39 · 3 answers · asked by greddy_civic 1 in Chemistry

For you consideration:

Exhibit A:
http://antwrp.gsfc.nasa.gov/apod/image/0709/CFHQS_coop_36.jpg

Exhibit B:
http://antwrp.gsfc.nasa.gov/apod/image/0709/rhooph_noao.jpg

2007-09-24 06:33:08 · 2 answers · asked by Belzetot 5 in Astronomy & Space

2007-09-24 06:33:01 · 2 answers · asked by Anonymous in Biology

How many grams of citric acid are contained in a 27.0ML sample that requires 37.6ML of 1.05 m for NAOH neutralization to occur?



Give the formula of the calcium salt of this compound.

2007-09-24 06:32:19 · 3 answers · asked by stranger 1 in Chemistry

A. remains constant
B. decreases
C. stratifies
D. increases

2007-09-24 06:31:45 · 5 answers · asked by LaKeshia H 1 in Earth Sciences & Geology

2007-09-24 06:29:02 · 4 answers · asked by Beme 2 in Physics

2007-09-24 06:28:57 · 3 answers · asked by Anonymous in Biology

2007-09-24 06:22:58 · 4 answers · asked by Fee 2 in Chemistry

The Power Because of a Poor transformer can be 80 Volts
When we run the fridge for example or water Pump it all runs on Lower Voltage (Its Not Good) but is it costing us MORE or Less to operate these things or is it the same ? What is the relationship between Voltage and Kilowatt hours?

2007-09-24 06:21:44 · 6 answers · asked by jojomontreal2000 2 in Physics

2007-09-24 06:19:13 · 6 answers · asked by veondra r 1 in Chemistry

I quote this from the wikipedia((Residual current devices)) ((It cannot protect against electric shock where current flows through a person from phase to neutral or phase to phase, for example where a finger touches both live and neutral contacts in a light fitting. It is virtually impossible to provide electrical protection against such shocks as there is no way for a device to differentiate between current flow causing an electrical shock to a person and normal current flow through an appliance)) is it really impossible or our existing knowledge falls short of such acheivment?.

2007-09-24 06:18:00 · 2 answers · asked by moh 1 in Engineering

the temperature will rapidly go down to almost absolute zero.

Then, how would the surface of Earth look like?

2007-09-24 06:10:31 · 2 answers · asked by Alexander 6 in Physics

Can someone help me with this truth table:


H= wx + xy' + wx'z' + xyz' + w'xy'

2007-09-24 06:08:41 · 2 answers · asked by chs_soccer_02 2 in Engineering

accel of gravity is 9.8m/s^2

what is the magnitufe of the acceleration of the elevator?

What is its direction?

2007-09-24 06:05:42 · 3 answers · asked by michael 1 in Physics

2007-09-24 05:59:54 · 22 answers · asked by youboob 1 in Astronomy & Space

2007-09-24 05:58:53 · 11 answers · asked by Anonymous in Astronomy & Space

Are the States in the "Deep South" region of the United States really at a lower elevation than the northerm and western states? If so, can anyone recommend websites that show illustrated graphs and provide data and such about the United States in general? Thank you very much!

2007-09-24 05:58:39 · 2 answers · asked by Jowe 1 in Earth Sciences & Geology

argument with a friend and he believes you can copyright anything which is written

2007-09-24 05:57:29 · 6 answers · asked by Anonymous in Mathematics

i need proper scientific answer.

2007-09-24 05:56:55 · 2 answers · asked by Haider 1 in Physics

2007-09-24 05:55:02 · 4 answers · asked by cluckcluck 1 in Chemistry

Determine the stopping distances for an automobile with an initial speed of 95 km/h and human reaction time of 3.0 s for the following accelerations.
(a) a = -4.0 m/s2
(b) a = -8.0 m/s2

2007-09-24 05:50:32 · 2 answers · asked by hahahahahaha 1 in Physics

2007-09-24 05:48:11 · 11 answers · asked by Cristian 3 in Parapsychology

2007-09-24 05:48:00 · 3 answers · asked by veondra r 1 in Chemistry

2007-09-24 05:46:28 · 6 answers · asked by Deutschjoe 3 in Mathematics

A.Loess
B.Erratics
C.Eskers
D.Drumlins

2007-09-24 05:45:19 · 3 answers · asked by Anonymous in Geography

2007-09-24 05:44:07 · 10 answers · asked by Anonymous in Medicine

1) a)why is lead(2) nitrate used rather than lead(2) sulphate?

b) what is removed from the surface of these metals when they are cleaned?

c) why are sodium and calcium not used in the expeirment?

d) which is the most reactive metal used?

e) predict the result of adding lead to silver nitrate solution?

2007-09-24 05:42:14 · 1 answers · asked by Sara *Life is so unlike theory* 5 in Chemistry

An integrated circuit or computer chip consists of a Si wafer with patterns of copper wires attached to the surface. During normal operation the chip may heat up and cause debonding of the Cu wires from the Si surface. This is because:




1. The Si expands more when it is heated

2. The Cu is an electrical conductor and Si is an insulator

3. The Si is a semiconductor

4. The Cu has a higher coefficient of thermal expansion

2007-09-24 05:36:47 · 2 answers · asked by Anonymous in Engineering