Science & Mathematics - 20 November 2007

Urn A contains six white and seven black balls. Urn B contains three white and eight black balls. A ball is drawn from urn A and then transferred to urn B. A ball is then drawn from urn B. What is the probability that the transferred ball was black given that the second ball drawn was white?
If necessary, round your answer to two decimal places.

2007-11-20 07:31:31 · 1 answers · asked by Anonymous in Mathematics

Two people start at the same place and walk around a circular lake in opposite directions. One has an angular speed of 1.80E-3 rad/s, while the other has an angular speed of 3.60E-3 rad/s. How long will it be before they meet?

Do I use w = 2(pi)/T?

Thanks!

2007-11-20 07:29:53 · 2 answers · asked by Anonymous in Physics

2007-11-20 07:27:06 · 7 answers · asked by amt_ashley_23 1 in Zoology

2007-11-20 07:27:02 · 5 answers · asked by rissa_leonard 1 in Other - Science

A digital watch battery draws 0.20 milliamperes of current, which is provided by a mercury battery whose net reaction is:

HgO(s) + Zn(s) --> ZnO(s) + Hg(l)

If a partially used battery contains 0.70 g of each of these four substances, for how many hours will the watch continue to run?

2007-11-20 07:23:12 · 3 answers · asked by Peter 2 in Chemistry

Four beakers of a solution all have a pH of 9.75. If a few drops of (1) Thymol blue, (2) Bromphenol blue, (3) Bromthynol blue, and (4) Phenolphthalein were placed in each beaker separately, what would be the four colors observed? (Enter the letters corresponding to the colors in order, e.q. ABCD, BDCA, etc.)

A) red or pink
B) yellow or orange
C) blue
D) purple or violet
E) colorless

2007-11-20 07:22:31 · 1 answers · asked by Peter 2 in Chemistry

A bullet is show through a musket 600m/s. The musket is .9m long with what acceleration is the bullet being shot?

2007-11-20 07:22:27 · 1 answers · asked by Rachel P 1 in Physics

The pH of an 0.018 M solution of weak acid A is 2.55. The pH of an 0.042 M solution of weak acid B is 3.06. The pH of an 0.089 M solution of weak acid C is 5.10. Identify the three acids from among those listed below. Find Ka values online.

A) HNO2
B) HF
C) HCHO2
D) HC7H5O2
E) HC2H3O2
F) H2S
G) HClO
H) H3BO3
I) HCN
J) None of the above

2007-11-20 07:21:54 · 1 answers · asked by Peter 2 in Chemistry

pile in the shape of a cone whose base diameter and height are always equal.How fast is the height of the pile increasing when the pile is 10 ft high?

2007-11-20 07:20:45 · 1 answers · asked by asddas a 1 in Mathematics

A customer at Cavallaro's Fruit Stand picks a sample of 5 oranges at random from a crate containing 40 oranges, of which 4 are rotten. What is the probability that the sample contains 1 or more rotten oranges?

2007-11-20 07:18:03 · 4 answers · asked by Anonymous in Mathematics

The pH of an 0.041 M solution of weak acid A is 2.37. The pH of an 0.024 M solution of weak acid B is 2.90. The pH of an 0.097 M solution of weak acid C is 5.08.

2007-11-20 07:18:01 · 3 answers · asked by Chem 111 1 in Chemistry

2007-11-20 07:14:42 · 2 answers · asked by Anonymous in Weather

I know that deciduous trees go dormant in the winter to conserve energy or water, but why do evergreens not have to go dormant in the winter.

2007-11-20 07:13:28 · 2 answers · asked by Anonymous in Botany

2007-11-20 07:12:25 · 4 answers · asked by Anonymous in Botany

What I mean is if ingredients have, say, 50kcal per 100g serving, would the label say 50kcal or 42kcal?

2007-11-20 07:12:18 · 1 answers · asked by Alexander 6 in Physics

2007-11-20 07:02:44 · 14 answers · asked by Reenie: Mom of Marine 6 in Weather

2007-11-20 07:02:16 · 9 answers · asked by shawna 2 in Mathematics

The number of ways of choosing 4 people from 12 is the same as the number of ways as choosing 8 people from 12 people. I don't understand this. Can someone explain why these tasks can be done in the same number of ways?

My logic just don't understand this, but I do know it is true.

2007-11-20 06:59:53 · 2 answers · asked by Lisa 4 in Mathematics

I am really into astronomy, and for my last birthday, my parents gave me a pair of 10x binoculars. I want to see Saturn's rings more than anything else in the sky, though there's a lot more I want to see. I recently read that one needs at least a 25x telescope to see the rings, but a book I borrowed from the library says one would need a telescope or a good pair of binoculars to get a good view.
So I'm really confused right now. Would someone please tell me if my binoculars will work? I would appreciate it.
Thanks!

2007-11-20 06:59:44 · 15 answers · asked by shyviolet 3 in Astronomy & Space

Is it possible for any of the aforementioned storms to cross the equator?

2007-11-20 06:59:22 · 4 answers · asked by Anonymous in Weather

I am concerned about something I have recently been told. DO NOT microwave anything plastic or the chemicals from the plastic will be absorbed in your food

2007-11-20 06:58:09 · 4 answers · asked by useless info 1 in Chemistry

A machine produces open boxes using square sheets of metal. The machine cuts equal sized squares measuring 3 inches on a side from corners and then shapes the metal into an open box by turning up the sides. If each box must have a volume of 75 cubic inches, find the length and width of the open box

2007-11-20 06:56:07 · 6 answers · asked by laker19 1 in Mathematics

Enormous numbers of microwave photons are needed to warm macroscopic samples of matter. A portion of soup containing 330. g water is heated in a microwave oven from 30.°C to 90.°C, with radiation of wavelength 1.55 10-2 m. How many photons are absorbed by the water in the soup?

2007-11-20 06:55:19 · 1 answers · asked by Ruby Winter 2 in Chemistry

is zimbabwe considred a third world country

2007-11-20 06:53:28 · 9 answers · asked by BONNiiE MAE 1 in Geography

2007-11-20 06:53:27 · 6 answers · asked by PDF 2 in Mathematics

2007-11-20 06:51:17 · 4 answers · asked by draydaze 2 in Mathematics

the length is 6cm and width 10cm and the mini squares are 3cms

2007-11-20 06:46:33 · 1 answers · asked by Anonymous in Mathematics

A man attempts to move a stationary object that weighs 152 N. The coefficient of static friction is .35 and the kinetic friction is .27

1. How much force must be applied to get the cabinet moving?

2. If the same force required to start the motion is applied to the cabinet after it starts to move, what is the cabinet's acceleration?

please help me!

2007-11-20 06:43:42 · 2 answers · asked by hotmvper2k3 1 in Physics

Three charges are at the corners of an
equilateral triangle, measuring 0.5 m on
each side. The charges are:
q1= 2 μC, q2= 7 μC, q3 =-4 μC
1. Calculate the electric field at the position
of the 2 μC due to q2 and q3.
2. Use the field to determine the force on
q1.

2007-11-20 06:41:06 · 1 answers · asked by Anonymous in Physics

2007-11-20 06:40:57 · 9 answers · asked by Ken B 1 in Mathematics