Science & Mathematics - 27 January 2007

and returns at the same speed. At the same time another man leaves from Point A to point B at an average speed of 30 miles an hour and returns at an average of10 miles an hour. Who gets back first? Commonsense tells me that they will get back at the same time, both having averaged 20mph but a collegue insists that one would get back earlier and there is a discrepancy I can't work out. The second person will be half-way back when the first person arrives at point B but then will reduce his speed to a third, having a quarter of the distance left. Can anyone explain this in a simple mathematical model and put us out of our misery?

2007-01-27 02:37:47 · 16 answers · asked by checkmate 6 in Mathematics

A triangle has sides of lengths 9, 10, and 11. Then the number of degrees in the smallest angle of this triangle, correct to the nearest tenth of a degree, will be

2007-01-27 02:37:17 · 4 answers · asked by chris 2 in Mathematics

If you say both the stem and bulb? Then why? doesn't the stem decide sensitivity and not range?

2007-01-27 02:35:46 · 1 answers · asked by Chocolate Strawberries. 4 in Physics

18.Combine like terms.
2w – 3x – 8w
A)–w – 8x
B)–9w + x
C)–9wx
D)–6w – 3x













20.Multiply.
a4b2 ab3
A)a5b5
B)a4b5
C)ab6
D)ab5

2007-01-27 02:34:25 · 3 answers · asked by Dave 4 in Mathematics

possible answers...

+2, +1

+2, -1

+1, +2

+1, -2

2007-01-27 02:30:12 · 5 answers · asked by Doug 2 in Mathematics

2007-01-27 02:29:42 · 7 answers · asked by miss 2 in Physics

Why? Why not a cube shape or even extrememly oblong? Or shaped like a 3D pancake???

2007-01-27 02:29:37 · 3 answers · asked by Tiff 5 in Astronomy & Space

2007-01-27 02:26:53 · 8 answers · asked by Simon & Em M 3 in Earth Sciences & Geology

looking to buy a pearl ring etc for a set but confused by all the variations,obviously simulated is fake are the others real pearls?

2007-01-27 02:24:13 · 4 answers · asked by Simon & Em M 3 in Earth Sciences & Geology

I would like to know how much NaCl in grams i must use per litre of distilled water.
Thx

2007-01-27 02:22:17 · 2 answers · asked by anwar r 1 in Chemistry

is it 3 ?

2007-01-27 02:22:14 · 5 answers · asked by Olivia 4 in Mathematics

Spontaneous combustion is when a human can burst into flame within a second.

2007-01-27 02:20:25 · 7 answers · asked by Anonymous in Physics

i mean captured the energy (song) that is being played during the 70s. Cause energy cannot be destroy it only change into another form of energy.

2007-01-27 02:19:19 · 6 answers · asked by Anonymous in Physics

2x + y - 4 = 0 . - 4 = 0 .


Find an equation for a line which passes thru the point (1, -2) and which is perpendicular to the line given by 2x + y - 4 = 0 .

possible solutions

x - 3y - 7 = 0

x - y - 3 = 0

x - 2y - 5 = 0

x - 4y - 9 = 0

2007-01-27 02:17:45 · 6 answers · asked by Doug 2 in Mathematics

2007-01-27 02:16:00 · 7 answers · asked by Robert M Mrok (Gloom) 4 in Physics

Does taking a laxative during the onset of a cold help ?

2007-01-27 02:15:14 · 5 answers · asked by ben 1 in Medicine

2007-01-27 02:13:49 · 5 answers · asked by Canada A 1 in Biology

I was trying to figure out how to produce magnetized material that would behave much stronger than normal magnet. I am guessing it could be metal of perfect mineral structure and high density – some kind of “diamond” among metal materials. As I know it is still easier to find and mine diamonds than produce them, so I tried to find an origin place of such new mineral. It couldnt be the earth surface, where even diamonds are rare. This new kind of metal must reguire diffrent enviroment... much stronger preasurre but not such high temperature like under Earth surface. So why not Mars?

2007-01-27 02:13:30 · 4 answers · asked by Robert M Mrok (Gloom) 4 in Astronomy & Space

2007-01-27 02:13:26 · 3 answers · asked by angel_4_life_88_2002 1 in Chemistry

2007-01-27 02:11:14 · 1 answers · asked by angel_4_life_88_2002 1 in Chemistry

Universe space with no gravity rather sounds as expedition full of disadvantages and problems dificult to solve out, but for me it isnt bad idea. Colonies in space will give you new advance in gardening, metalurgy, travel, medicine and exploration. Plants will evolve to use their life power to create more nutrients in place of need of solid structure, size and aditional organs needed in gravity and in Earth ecosystems. Space metalurgy will compete efficiently with nanotechnology, because in space molecules have behaviour free from gravity, what will give posibility of full magnetic control and diffrent fraction of alloy ingredients. Centrifugal force has bright future in space travels, because it is the most efficient propulsion in space enviroment as far I know. Space colonizing with it is specifical feature, new plants, new branches in human evolution and wider knowledge will give you wisdom of medicine you only dream about for now.

2007-01-27 02:10:58 · 3 answers · asked by Robert M Mrok (Gloom) 4 in Astronomy & Space

possible solutions

1/x

(1 + x)/x

(1 - x)/(1 - 2x)

1 - x

or is it none of these

2007-01-27 02:08:46 · 5 answers · asked by Olivia 4 in Mathematics

could be one of these following answers...

4x - 3y - 2 = 0

4x + 3y + 2 = 0

4x - 3y + 2 = 0

4x + 3y - 2 = 0

or is none of these

2007-01-27 02:05:40 · 15 answers · asked by chris 2 in Mathematics

the method which i have got is using the KOH which is in powder form,but i have in liquid form,so how to make the solution?...thank you so much ...urgent...

2007-01-27 02:03:59 · 4 answers · asked by young_chemist 1 in Chemistry

2007-01-27 02:02:50 · 4 answers · asked by Canada A 1 in Biology

The rock is dark and it appears to be coarse-grained with pieces of quartz in it.

2007-01-27 02:02:42 · 3 answers · asked by Kimya 2 in Earth Sciences & Geology

2007-01-27 02:02:41 · 8 answers · asked by Anonymous in Chemistry

plzz

2007-01-27 02:00:13 · 1 answers · asked by jenz 2 in Engineering

2007-01-27 02:00:02 · 5 answers · asked by Anonymous in Mathematics

explain in about 6 steps, not too long, maybe 2 lines or sometin

2007-01-27 01:57:48 · 17 answers · asked by Anonymous in Geography