Science & Mathematics - 10 September 2007

This is a lab that we did in class, but the explanation makes no sense, we need to know the concepts for the test. In beaker 1, is plain distilled water. A slice of cucumber is put in it. In beaker 2, a slice of cucumber the same size is placed in a water and salt mixture. Let it sit for 45 mins. And wa-laaa! The slice of cucumber placed in distilled water is firm, and hard. The slice placed in the salt mixture is flimsy, and essentially--dead. It shrunk, and it wobbles. Why does the cucumber react so differently? What's the scientific explanation?

2007-09-10 09:49:23 · 4 answers · asked by <<<FM>>> 3 in Biology

Descride how gold can be seperated from a mixture of sand and dirt. What characteristic property of gold allows it to be separated in this way?

2007-09-10 09:46:50 · 5 answers · asked by Anonymous in Chemistry

aristotle believed wood was a combination of fire, water, and earth. use his four-elements theory to explain why a wooden boat floats on water.

2007-09-10 09:46:29 · 19 answers · asked by alhan 1 in Physics

i.e., how much will the volume of the solution differ from 120 mL?

Thanks in advance.

2007-09-10 09:46:24 · 2 answers · asked by Anonymous in Chemistry

I have to write a paper on ecology in terms of population growth and human activites on the environment. I have to be sure to mention the examination of the dynamics of population growth on the environment, explanation of the concept of regulation of population growth through community interactions and the evaluation of the effects of human activites on ecosystems and the biosphere. I do not care for science at all. I have done research but am still confused and do not know where to even begin my paper or what to include in it. It needs to be 700-1,050 words and sound scientific. Any pointers, information, topics, explanations, etc. Help me please.

2007-09-10 09:46:15 · 2 answers · asked by crystal nw 2 in Biology

When you divide the same units into something (like 10kg/5kg) the unit remains. I know the answer is 2 m/s, but how do I get there?

2007-09-10 09:45:19 · 2 answers · asked by seventhyearfalling 2 in Mathematics

2007-09-10 09:43:07 · 10 answers · asked by Anonymous in Physics

somebody, go do it and let me know what happens.

2007-09-10 09:40:29 · 8 answers · asked by Anonymous in Other - Science

What kind of jobs and stuff could I get??

2007-09-10 09:39:39 · 4 answers · asked by Sandy 4 in Biology

The report was about picking an animal to be. I picked a polar bear. Here is what I've got so far:

If I could be any animal, I would be a polar bear because they swim a lot, and I really like to swim. Their fur is really thick so it keeps them warm in the cold water way up north. They are the biggest of all the bears and I think it would be really awesome to be big like that. The only other animal that tries to hunt them is humans, which is pretty bad because I wouldn’t have a weapon to defend myself, besides me and maybe other polar bears. My favorite food would be seals, because they really get on my nerves. My favorite thing would probably be my white fur because it keeps me warm and it really pretty.
The only bad thing about being a polar bear would be going extinct. It wouldn’t be much fun being dead.

2007-09-10 09:39:37 · 3 answers · asked by lizzy 2 in Zoology

2007-09-10 09:39:35 · 10 answers · asked by Anonymous in Astronomy & Space

2007-09-10 09:37:02 · 5 answers · asked by alhan 1 in Physics

2007-09-10 09:35:43 · 19 answers · asked by Anonymous in Astronomy & Space

2007-09-10 09:35:02 · 4 answers · asked by la la la 2 in Geography

its for my chemistry homework, and i dont understand that bit...

thanx again xx

2007-09-10 09:34:17 · 1 answers · asked by -x-lollie-x- 1 in Chemistry

A car sits in an entrance ramp to a freeway, waiting for a break in the traffic. The driver sees a small gap between a van and an 18-wheel truck and accelerates with constant acceleration along the ramp and onto the freeway. The car starts from rest, moves in a straight line, and has a speed of 10 m/s (22 mi/h) when it reaches the end of the 115 m long ramp.

(a) What is the acceleration of the car?
m/s2
(b) How much time does it take the car to travel the length of the ramp?
seconds
(c) The traffic on the freeway is moving at a constant speed of 10 m/s. What distance does the traffic travel while the car is moving the length of the ramp?
meters

2007-09-10 09:33:30 · 1 answers · asked by Walachka 3 in Physics

Let me know anything you know about this question. Thank you!

2007-09-10 09:33:13 · 1 answers · asked by robert johnson 2 in Chemistry

how do they predict weather with technology

2007-09-10 09:32:54 · 2 answers · asked by tammarin r 1 in Weather

In a biological membrane (below, right), some components exhibit limited lateral mobility in the plane of the membrane, and other components move laterally quite rapidly. Which one of the following best describes a component of the membrane which can move laterally very rapidly?
a) Phospholipids that are covalently bound to the extracellular matrix.
b)Membrane proteins that are bound to the internal cytoskeleton.
c) Proteins that are integral membrane proteins.
d) Glycoproteins that are in the membrane.
e) Phospholipids that are in the membrane.
Thanks guys! I already have an answer in my mind, but I just want to confirm it.

2007-09-10 09:31:25 · 1 answers · asked by bseo87 1 in Biology

What is 12 - 54 divided by [5 + 2 (8 divided by 4) ]

2007-09-10 09:30:50 · 4 answers · asked by lindsey12 1 in Mathematics

2007-09-10 09:29:03 · 6 answers · asked by Porygon 1 in Astronomy & Space

a farmer has 60m of fenceing to make a pen for a goat. he wants to make the area of the pen as large as possible.
The length of the pen is x meters
1)write down an expresision in terms of x for the width of the pen
2) find an expression for the area of the pen
3) write this expression in the completed square form
4) what value of x make the area af the pen as large as possible. What is this area?

2007-09-10 09:27:36 · 7 answers · asked by Anonymous in Mathematics

I understand about the human factors such as people building on flood plains etc, environment agency not putting out warnings etc etc.

What i want to know is what really caused the floods, and how far is global warming to blame? or is it not?

2007-09-10 09:25:35 · 2 answers · asked by Anonymous in Weather

how many 10s 100s and 1000 are in 15,000,000

2007-09-10 09:25:00 · 1 answers · asked by notmygame 6 in Other - Science

What is 12 - 54 divided by [5 + 2 (8 divided by 4) ]

2007-09-10 09:23:53 · 4 answers · asked by lindsey12 1 in Mathematics

2007-09-10 09:22:43 · 2 answers · asked by Anonymous in Other - Science

1. Just out of College
2. Passed FE but hasn't taken PE exam yet
3. Just Passed PE
4. Project Engineer
5. Owner of Engineering Firm.

2007-09-10 09:17:02 · 4 answers · asked by civil_seismic_eng 4 in Engineering

My teacher went over this stuff so fast, I couldn't get all of the notes. The question is this:

Using the concepts of force, impulse and time (F*t), briefly explain why an airbag is a beneficial safety feature.

I need to understand this stuff for our test next week. There's no textbook for this source and it's a lecture hall course, so office hours for my professor are pretty filled up. Can someone explain this to me?

Thanks

2007-09-10 09:16:53 · 4 answers · asked by seventhyearfalling 2 in Physics

12(10-(5 exp.2 -6)3/6)

2007-09-10 09:16:52 · 1 answers · asked by Anonymous in Mathematics

Penguins don't have feathers nor do they fly, so what makes them be a bird?

2007-09-10 09:16:25 · 18 answers · asked by music 2 in Zoology