Other - Science - July 2007

I have noticed that any kind of bread - bagels, buns, rolls, loaves - when kept in a plastic bag, in the refrigerator, dries out on the bottom, while the top gets soggy. What's up with this water migration? It doesn't happen to bread kept in plastic bags at room temperature...

2007-07-18 08:53:05 · 4 answers · asked by psychetechnic 2

Hi. I've tried to find the definitive average figure of the amount of CO2 sequestered by trees, however it seems impossible to find a reliable figure as the variables involved mean I keep getting different answers.

It all depends on the type of tree, where it grows, how healthy it is, how old it is, etc, ect. Therefore does anyone know of any formula or definitive answer that will actually tell me how much CO2 a healthy broadleaf tree in the UK (for example) will absorb from sapling to maturity (let's say 50 years) and each year thereafter??

PLEASE don't be random - I really do need to have a proper scientific answer to this Q for research I'm doing for my charity to challenge the carbon offsetting industry.

Thank you very much.

2007-07-18 05:57:35 · 4 answers · asked by Anonymous

I know that sublimation is the probable cause that they shrink down to nothing, but how do i keep this from happening? ty
:)

2007-07-18 05:16:10 · 7 answers · asked by Twinklestar 6

2007-07-18 04:51:45 · 5 answers · asked by laura b 2

Have it appraised and maybe have some jewelry made from it. My sister is a designer, but she lives far away and is too busy to help much. Thanks!

p.s. Its purple, black, grey and brown. Its about the size of a fig. I found it on the ground by the lake.

2007-07-18 03:59:33 · 5 answers · asked by Sleek 7

The latent heat of fusion (solid become liquid) for ice is 79.8 cal/gram. How much ice can we melt with 1000 calories of heat?
(a)Read the introduction carefully. Identify the key pieces of information required to solve this problem.
(b)Identify the extraneous information in the background reading
c) Explain your strategy for solving this problem.
(d)Solve the problem. How much ice can you melt with 1000 calories of heat?
Hints:

The formula is:
The amount of heat = (mass of the material) x (latent heat of fusion):
Q = mLf
where Q is the amount of heat in calories;
m is the mass of the material in grams;
Lf is the latent heat of fusion in calories/gram.

In this problem, you are provided the amount of heat, Q, and the latent heat of fusion, Lf. You will have to rearrange this equation and solve it for mass, m.

Which would require more heat, melting 500 g of 0 C ice or turning 500 g of 100 C water into steam?
A 500 g sample of an unknown material requires 750 calories of heat to raise its temperature by 50 C. Use Equation (1) and Table 6.1 to identify the material.The formula used to calculate the amount of heat required to heat the material without phase change is:

Amount of heat required = (specific heat capacity) x (mass of the material) x (change in temperature)

or

Q = C * m * ∆T

where C is the specific heat capacity of the material in cal/g 0C;
m is the mass of the material in grams;
∆T is the temperature change, 0C.

2007-07-18 03:49:43 · 1 answers · asked by deebeals 1

2007-07-18 01:54:36 · 4 answers · asked by vanessa 1

....where it goes. Can anyone shed some light on this phenomenon.

This is 21 grams of un accountable weight.

2007-07-18 01:53:15 · 13 answers · asked by Anonymous

and what causes some materials to transfer heat better?

2007-07-17 22:54:38 · 4 answers · asked by Anonymous

My dad was a perpetual thermostat Nazi, so I grew up getting used to sweating at night in 78 degrees temps and utterly freezing in the winter with the thermostat down to 64.

Now my husband complains because I am used to these temperature settings but he is not, and we get in fights over it. His dad was one of those thermostat Nazis too. But now he says "I earn the money, I pay the bills, and if I need the thermostat set to 72 at night so I can sleep, that's how it has to be!"

The problem is, now when he sets it to 72 at night in the summer, I'm freezing. Or when he sets it to 72 in the winter, I'm dying of heat.

He also complains that my body temp goes up 2-4 degrees every 4 weeks... PMS hormones... he says "You're thermonuclear again!" and hits the thermostat down... and then I'm freezing.

But I don't know how to answer him when he hits me with the simple logic: why is 72 in the summer "too cold" while 72 in the winter is "too hot"?

Why does it feel that way?

2007-07-17 19:42:19 · 6 answers · asked by Anonymous

Eg. Some people tell us to send e-greetings instead of regular cards, because we then consume less paper.

But computers are still made from plastic (petroleum), and it and networks run on electricity which still puts a burden on resources.

2007-07-17 18:02:23 · 2 answers · asked by Anonymous

Can I use city water or some other type of water?

2007-07-17 17:10:44 · 4 answers · asked by Anonymous

2007-07-17 15:54:48 · 8 answers · asked by Raghavendra R 5

2007-07-17 15:28:44 · 2 answers · asked by Anonymous

Step 1: get donations or buy 20-30 concrete stepping stones (2" or so thick, round or square, very flat) and a gross or 2 of Dixie cups. Report weight of each stone.
Step 2: on a very level base (check it), chalk an outline of the stones. Arrange 9 or 16 cups in even spacing. Place a stone flat on the cups.
Step 3: repeat to see how high a stack can be made before collapsing.
Step 4: Video tape as stack builds - ideally with 2 cameras, one showing overall scene and one showing bottom 3 layers.
Step 5: Post video to UTube
Question: Does the tower tip significanly to one side or fall basically straight down?
Build another tower, but stop a layer or two before it collapses. Use a rod to punch out cups 25% of the way down from the top until the top starts to fall. Record falling pattern, does building fall straight down. This simulates fall of Buildings 1 & 2 of World Trade center. (Optional: place a bit of flour on each layer and paper sides to show blow out.)

2007-07-17 14:07:36 · 1 answers · asked by Mike1942f 7

2007-07-17 13:28:24 · 12 answers · asked by mystery 2

i need techniques on how to read faster

2007-07-17 11:33:24 · 3 answers · asked by Anonymous

I dont want to use any gas or co2 or anything that could explode.

2007-07-17 11:33:14 · 7 answers · asked by Michael P 1

im a senior in Highschool, and i don't know exactly what to major in, i know i want to work in either Physics or Chemistry, and at one point own a business, like a R&D firm if possible, and i am stuck on a few things.

What should i major in?
should i go for a PhD (id like to) in that
should i get a Bachelors, then stop and start working on the business then return?

any advice is appreciated

2007-07-17 10:14:41 · 1 answers · asked by Anonymous

i want to buy a generator for my travel trailer but dont know how much wattage i need, it has a new 110 refridgerator and a new ac also 110 and of course lights and 2 tvs with dvd players, i plug into 30 amps at the rv parks and seem ok but i want to buy a generator in case i cant get to an rv park,,all the generators i see say wattage on them, so how big do i go,, thanks everybody

2007-07-17 09:39:10 · 6 answers · asked by Anonymous

a)accelerating down a hill
b)going faster and faster
c)slowing down
d)maintaining a constant velocity.

2007-07-17 07:41:58 · 6 answers · asked by Lilly 1

would it be that hard for a human to make one?

2007-07-17 07:04:37 · 7 answers · asked by Heather 4

i ate a pearl wen i was small, thought it was some type of shinny pea?!

2007-07-17 07:01:53 · 8 answers · asked by Anonymous

What are some of the benefits of squeezing so much data into virtually every cell in the body?
Why did we not evolve with one central repository of DNA rather than having it replicated throughout the body?
Assume that the hereditary information carried in genes and DNA is responsible for a lot of the differences we observe in humans and other living things. How could just four different bases in DNA strands be responsible for the almost endless variety found in nature?

Yes it's Homework.. and Yes I need help.

2007-07-17 07:01:45 · 4 answers · asked by Anonymous

Okay sorry if the question was confusing but I had limited space. ill rephrase the question: If a car had its headlights on and was on the freeway moving, and nothing cant go faster than light, Isnt the speed of the cars getting added to the speed of light? So doesnt that mean that The light on the head light is moving faster than the speed of light? Anyone care to explain? (sorry if I put this one in the wrong catagory! I really didnt know)

2007-07-17 05:12:26 · 13 answers · asked by nanomot 1

2007-07-17 05:06:41 · 4 answers · asked by Anonymous

My parents bought a house and the EMF readings are really high. It seems that the source is outside the home in a certain direction. How can we find out what the source is and what can we do to protect ourselves from the EMF? Also, are there professionals that deal with this? What is their professional title?

2007-07-17 04:28:56 · 2 answers · asked by not 30 yet 2

cries some. Now here is my question. Do babies cry because of some evolutionary development that came about during the "dawn" of human evolution? I believe that almost everything that we do, by nature, we do because at some point in our evolutionary development, it was to our advantage to do that thing. It was a help in our survival. Babies cry when something is wrong. If they did not cry, very serious things might go unnoticed. So, do babies cry because of evolutionary lessons learned at the "dawn of time?"

2007-07-17 01:51:59 · 5 answers · asked by Bluebeard 1

I have a son who has red hair. Neither my husband nor myself have red hair (we both have medium-dark brown). I had heard that in order to have red hair it had to be on both sides of the family.

2007-07-16 22:55:51 · 8 answers · asked by Cindy B 2

MY BOOK DEALS WITH
1) THEORY FOR SOLUTION OF SUDOKUS
2)RECREATIONAL MATHEMATICS WITH BASIC THEORY

2007-07-16 21:31:12 · 4 answers · asked by krishna m 1