Science & Mathematics - 11 February 2007

2007-02-11 23:02:39 · 11 answers · asked by lack 1 in Zoology

1. How many electrons should be removed from a neutral object to give it a charge of = 1 uC?

2. How far apart should two electrons be placed so that the force of repulsion between them is
(a) 1N
(b) same as the weight of an electron on the surface of the earth

3. Two small metal spheres initially neutral are placed 3.0m apart. Now one billion electrons are transferred from one sphere to the other. Determine the charge on each sphere and the force between them.

4. The force of repulsion between two point charges placed 6.0m apart is 5.0 * 10^9 N. If one charge has twice the magnitude of the other, determine those magnitudes.

5. Two point charges of +6 uC and - 4 uC are placed in a plane at the points (6m,-2m) and (0m,4m). Determine the magnitude and the direction of force on each.

2007-02-11 23:00:50 · 1 answers · asked by Anonymous in Physics

If a drop of water is placed on a slide and examined under a microscope, the number of x of a particular type of bacteria present has been found to have a Poisson probability distribution. Suppose the maximum permissible count per water specimen for this type of bacteria is five. If the mean count for your water supply is two and you test a single specimen, is it likely that the count will exceed the maximum permissible count? Explain.

2007-02-11 23:00:29 · 1 answers · asked by KING CHAN 1 in Mathematics

2007-02-11 22:59:21 · 8 answers · asked by Anonymous in Chemistry

The building cracked, the lights dimmed and my chair wobbled!
(10.35 am, Lisbon, Portugal)

2007-02-11 22:57:48 · 9 answers · asked by Alyosha 4 in Other - Science

A company has five applicants for two positions: two women and three men. Supoose that the five applicants are equally qualifies and that no preference is given for choosing either gender. Let x equal to the number of women chosen to fill the two positions.
(a) Write the formula for p(x), the probability distribution of x.
(b) What are the mean and variance of this distribution?
(c) Contruct a probability histogram for x.

2007-02-11 22:57:00 · 2 answers · asked by KING CHAN 1 in Mathematics

How big would the world be, how much gravity would there be, and would life have developed as we know it?

2007-02-11 22:55:50 · 4 answers · asked by Alyosha 4 in Geography

2007-02-11 22:54:36 · 10 answers · asked by klyn-klyn 2 in Astronomy & Space

calculate the formula mass for:
- ammonium phosphate

please explain to me how i can work this out

2007-02-11 22:52:50 · 5 answers · asked by yassem1ne 2 in Chemistry

To determine whether of not they have a certain disease, 100 people are to have their blood tested. However, rather than testing each individual separately, it has been decided first to group the people in groups of 10. The blood samples of the 10 people in each group will be pooled and analyzed together. If the test is negative, one test will be suffice for the 10 people: whereas, if the test is positive each of the 10 people will also be individually tested and, in all, 11 tests will be made on this group. Assume the probability that a person has the disease is 0.1 for all people, compute the expected number of tests necessary for each group.

2007-02-11 22:52:38 · 2 answers · asked by KING CHAN 1 in Mathematics

2007-02-11 22:51:11 · 5 answers · asked by rohitvijaysharma 1 in Physics

how could you calculate the standard enthalpy of formation of sodium carbonate ?

2007-02-11 22:49:35 · 3 answers · asked by Anonymous in Chemistry

can u give me information regarding satellite?

2007-02-11 22:49:22 · 1 answers · asked by tomas 1 in Engineering

when i click on mouse goes to side top and bottom dont stay where i click

2007-02-11 22:45:29 · 3 answers · asked by tx2step49 1 in Zoology

2007-02-11 22:45:20 · 7 answers · asked by KES1234 1 in Mathematics

a balloon can be seen from two observations posts. From A, the angle of the elevation is 30degree and from B, it is 45degree. If the balloon is 1000m high, what is the maximum possible distance between A and B?


pls. help me what to do...

2007-02-11 22:43:03 · 3 answers · asked by Anonymous in Mathematics

In the diagram, AB=9 and AD=8. Two circles, centers E and F are tangent to each other and to X and M and N and Y respectively. If the radius of the smaller circle is 2, find the radius of the larger circle.
http://www.e-zgeometry.com/pow/pictures/27.gif

2007-02-11 22:42:22 · 4 answers · asked by Anonymous in Mathematics

2007-02-11 22:41:52 · 12 answers · asked by unclejul2002 1 in Weather

2007-02-11 22:37:25 · 8 answers · asked by Anonymous in Mathematics

Or European Zoos?

2007-02-11 22:37:16 · 4 answers · asked by Anonymous in Zoology

word or expression in the first column


__ aristotles theory of motion
__galileos theory of motion
__law of universal gravitation
__a=g
__mass
__weight
__projectile
__freely falling body
__w over g
__trajectory

a)bullet fired from a gun
b)9.8 m/s squared
c)a measure of the gravitational force on an object
d)path followed by a projectile
e)mass
f)a measure of inertia
g)all objects on earth fall with the same constant acceleration due to gravity in the absence of air
h)heavy objects fall faster than light objects
i)Fg=Gm1m2 over d2
j) uniformly accelerated motion

2007-02-11 22:36:34 · 1 answers · asked by paolo b 1 in Physics

2007-02-11 22:36:08 · 14 answers · asked by spatecarla@btinternet.com 1 in Mathematics

2007-02-11 22:35:33 · 6 answers · asked by zhaz 1 in Engineering

2007-02-11 22:34:28 · 1 answers · asked by curious 2 in Physics

Heat of fusion

Another purpose of stirring the mixture(water and ice) in the experiment?

2007-02-11 22:34:24 · 3 answers · asked by jppd12689 3 in Physics

can someone please help me?
solve -4(x-9) +2x = 3x-14

2007-02-11 22:33:12 · 12 answers · asked by Anonymous in Mathematics

What is the name of :
CH3
l
CH3-C≡C-CH2-CH3
l
CH3

2007-02-11 22:32:18 · 1 answers · asked by LoL... E 1 in Chemistry

Why, when atoms of elements are heated, do they give off light, even though sometimes this light is not visible?

I think I understand the basics. When an atom is heated, an electron can become unstable, jumping to a higher energy level where it is unstable. It returns to its lower energy level, releasing energy in the form of light.
However, I'd like to answer the question in more detail and with more understanding. How do you get white light? And why, when the light is passed through a spectroscope, does the image consist of seperate coloured lines?
And how can we identify an element by its emission spectra?
If you could help I'd be very grateful.

2007-02-11 22:30:31 · 3 answers · asked by Anonymous in Chemistry

I'll solve any math problem for ¢20, at least 5 problems I assume. Quickly and guaranteed quality.

2007-02-11 22:25:09 · 11 answers · asked by msknums 1 in Mathematics

there is a triangle with the same legs ( 2 of the sides are the same )
cos a =x1(root1), cos a=x2(root2), cos b=x3(root3)

2007-02-11 22:22:33 · 3 answers · asked by Ika K 1 in Mathematics