Science & Mathematics - 30 October 2007

2007-10-30 06:59:27 · 5 answers · asked by Rover 3 in Mathematics

If Nostradamus is right about the world ending in 2012, then why do his predictions go all the way to the 3700's?

2007-10-30 06:58:06 · 26 answers · asked by CharChar 5 in Astronomy & Space

I may be deciding to do them at university.

2007-10-30 06:55:00 · 5 answers · asked by Anonymous in Engineering

I may be deciding to do them at university.

2007-10-30 06:52:52 · 2 answers · asked by Anonymous in Engineering

See Step 11 on this company's device --- http://www.fluidmaster.com/pdf/400a_instructions.pdf

They are sending water down the over-flow pipe which is water lost down the drain for NO GOOD REASON AT ALL. My neighbor has defied this instruction and directed the water to fill inside the tank instead and there is no ill-effect. The re-directed water filled up the tank faster. Why would a commercial company ask their customer to waste water ? There must be a good reason ... Anybody knows why ?

2007-10-30 06:50:11 · 4 answers · asked by Anonymous in Engineering

1. While chopping down his father's cherry tree, George discovered that if he swung the axe with a speed of 25 m/s, it would embed itself 2.3 cm into the tree before coming to a stop
a) If the axe head had a mass of 2.5 kg, how much force was the tree exerting on the axe head upon impact? Explain your answer.
>>>I have no idea how to do this...
b) How much force did the axe exert back on the tree? Explain your answer.
>>>I have no idea how to do this either......

2. Jackson's favorite ride in Disneyland is the rollercoaster. The rollercoaster car and passengers have a combined mass of 1620 kg, and they descend the first hill at an angle for 45.0 degrees to the horizontal. With what force is the rollercoaster pulled down the hill?
>>I need help with this... T__T

2007-10-30 06:49:49 · 3 answers · asked by Anonymous in Physics

help me solve this

2007-10-30 06:47:19 · 7 answers · asked by Najaf R 1 in Mathematics

a zookeeper shoots a dart horizontally at a monkey. at the same instant, the monkey begins to fall from the tree. Will the dart hit the monkey?

2007-10-30 06:47:19 · 4 answers · asked by Anonymous in Physics

howto do this help!!!!!

2007-10-30 06:45:09 · 7 answers · asked by Anonymous in Mathematics

In ten(10) minutes Kali runs 1km. What was her speed in Km per hour?

2007-10-30 06:43:42 · 11 answers · asked by Anonymous in Mathematics

Which part of an atom has a mass approximately equal to 1/2000 of the mass of a common hydrogen atom?
a. nucleus c. proton
b. electron d. electron cloud

2007-10-30 06:42:42 · 5 answers · asked by -BrownEyedBeauty- 1 in Chemistry

2007-10-30 06:42:37 · 8 answers · asked by Anonymous in Mathematics

SeO2 (s) + KOH (aq) -->

I know H2SeO2 is formed but wat happens with the K

2007-10-30 06:42:24 · 3 answers · asked by gabucha 1 in Chemistry

2007-10-30 06:42:12 · 16 answers · asked by Hamurabi 2 in Geography

If there are 20,000 light bulbs in a row, and they are all OFF.
All of the lights have one of them strings to turn it from on to off, or off to on..
First go down the row and pull every lights string.
So you pull lights 1,2,3,4,5...
Now do it again pulling every 2nd lights string
So you pull lights 2,4,6,8,10...
Now the 3rd, 3,6,9,12,15..
4th, 4,8,12,16...
Keep doing this until you get to the end. Then end is when you pull every 20,000th lights string...(which means you only pull the string of the last light)

At the end, how many lights are ON?
And explain which ones will be on...

Have fun...

2007-10-30 06:40:10 · 2 answers · asked by Randy C 2 in Mathematics

a hydrocarbon is subjected to combustion analysis. a sample of the compound gave 0.314g CO2 and 0.129g H2O.
a)calculate the mass of carbon and hydrogen in the sample

b) find the no of moles of carbon and hydrogen in the sample of the compound

c)what is the empirical formulae

2007-10-30 06:39:18 · 2 answers · asked by Anonymous in Chemistry

Please show me how to do this:

An object moves along the x-axis at a rate of 5 m/s, so its position is at (b, 0) with b' = 5. Find the rate of change of the distance between the object and the parabola y = x^2, at the time when the point on the parabola nearest to the object is the point (1, 1).

Thank you in advance

2007-10-30 06:38:30 · 4 answers · asked by Anonymous in Mathematics

What is the intensity?

2007-10-30 06:35:50 · 1 answers · asked by kntagler 1 in Physics

How do all the countries and states stick to the earth?

2007-10-30 06:34:45 · 4 answers · asked by ANNA 2 in Earth Sciences & Geology

Determine whether the pair of functions f and g are inverses of each other.

f(x) = x + 7 and g(x) = x - 7

2007-10-30 06:32:43 · 3 answers · asked by Brick Top 1 in Mathematics

I am doing some silver soldering and I have to use jewellers pickle which is acid based, but mild. What kind of container can I use. I believe some kind of poly plastic is suitable.. Anyone know please?

2007-10-30 06:30:03 · 2 answers · asked by michelle l 1 in Chemistry

2007-10-30 06:30:02 · 7 answers · asked by priscilla r 1 in Mathematics

2007-10-30 06:28:31 · 7 answers · asked by Anonymous in Biology

2007-10-30 06:27:06 · 8 answers · asked by Anonymous in Engineering

2007-10-30 06:27:04 · 4 answers · asked by Anonymous in Chemistry

Does anyone know any websites where I can learn the material.. besides math SOS?

2007-10-30 06:26:54 · 2 answers · asked by yahoo answers 1 in Mathematics

2007-10-30 06:26:27 · 1 answers · asked by Anonymous in Chemistry

can u please explaiin how to do problems like

c(7,3)


can u work out the problem cuz i forgot how to do it and i have a whole problem of these to

2007-10-30 06:25:35 · 3 answers · asked by cutejaz18 1 in Mathematics

Ellingham diagram is a plot of change in STANDARD free energy change
with temperature for various reactions like the formation of
oxide,sulphides etc.
STANDARD FREE ENERGE CHANGE is the change in energy measured at
S.T.P.Hence its a constant.
My question is how can it be compared at different temperatures as done in ellingham diagrams??
A constant cannot be varied with any variable...

2007-10-30 06:25:15 · 1 answers · asked by shridhar m 1 in Engineering

Solve the equation.

ln 6 + ln (x - 1) = 0

2007-10-30 06:24:49 · 3 answers · asked by Brick Top 1 in Mathematics