Science & Mathematics - 18 December 2007

it can be an animal or person but could u explain it. do u know why?

2007-12-18 06:20:41 · 11 answers · asked by animallover 2 in Paranormal Phenomena

Hi,

I want to immerse a diode in various water baths but I'm not quite sure how I can do this as I can't insert a diode directly into a water bath. At the same time though, I want the diode to be able to respond to the change in temperature surrounding the diode.

I had a look at heat shrink tubing on the internet but that will "shrink" the heat. Also, another way (thanks to amansscientiae) is to place the diode directly in oil inside a test tube. Would it be ok for me to do this though? (As I will need to connect wires on both sides of the diode.)

2007-12-18 06:19:55 · 5 answers · asked by Anonymous in Physics

2007-12-18 06:17:09 · 16 answers · asked by Anonymous in Astronomy & Space

Earth is about 150 million km from the sun. The radiation from the sun travels at 300,000 km/s. How long does it take for the radiation from the sun to reach earth?
Thanks for all yur answers!

2007-12-18 06:17:09 · 6 answers · asked by Anonymous in Earth Sciences & Geology

And is an area of 1 km^2 for a solar power tower enough to produce energy for five houses? can you make an approximation of how much it could supply?

2007-12-18 06:12:28 · 3 answers · asked by Anonymous in Other - Science

One more word problem, please help me:

The profit (in dollars) from the expenditure of x thousand dollars on advertising is given by P(x) = 1000 + 32x - 2x^2. Find Marginal profit at following expenditures. Then in each case, say whether firm should increase the expenditure and why.

a.) x = 8

b) x = 6

c) x = 20


Please don't tell me its easy, it is hard for me. Please show work and explain how do it.

2007-12-18 06:07:38 · 5 answers · asked by Anonymous in Mathematics

A person doing a chin-up weighs 700 N, disregarding the weight of the arms. During the first 24.0 cm of the lift, each arm exerts an upward force of 358 N on the torso. If the upward movement starts from rest, what is the person's speed at this point?
m/s

2007-12-18 06:05:19 · 4 answers · asked by Anonymous in Physics

I heard a male lightning bug it the only lightning bug that glows,(The female does not glow)
What makes it glow?

2007-12-18 06:05:18 · 3 answers · asked by Anonymous in Zoology

If I have a 3V Battery and connect it to a bulb of resistance 12 ohm I should have a current of 0.25A flowing through.

So then if I connect two 3V Batteries in Parallel, should I still have 0.25A in the circuit?

I always thought that batteries in parallel doubled the current in the circuit but I have found it to be different. So what increases. Does the maximum load of the circuit increase? I mean does it mean that this setup could provide up to double the current than that of only one battery?

2007-12-18 06:04:57 · 7 answers · asked by alanjb 1 in Physics

2007-12-18 06:03:03 · 10 answers · asked by Narok 1 in Physics

ok i dont have a clue what these answers are so please help me out im usally ok in math but im stuck on these answers and please dont be rude and answer like an idiot



the mass of a pineaple?
6,700 cm = __ m
explain how the outliner in the data effects the mean
3,2,6,3,5,4,15,4,3

4.1 + c = -1.2

ok those are all the problems i need help with now please answer if you want those ten points answer a real answer dont put something dumb in like 35435 cause that wont help

2007-12-18 06:02:56 · 4 answers · asked by Serena Van der Woodsen 2 in Mathematics

one of those questions i've never had the answer to. So if astronauts suited up, and succesfuly left the earths atmosphere into space towards the moon - how long in days would it take before they entered into The moons atmosphere ?

2007-12-18 06:02:53 · 4 answers · asked by Anonymous in Astronomy & Space

Like when and where it was discovered, and who discovered it, and what type of element it is, from which family it came from, what period, and its isotopes and uses.. Its for a project for science. =] and anythiing else that is useful

2007-12-18 06:00:03 · 7 answers · asked by mboylover294 1 in Chemistry

wondering

2007-12-18 05:59:26 · 3 answers · asked by Anonymous in Physics

I have always known that a Black Hole pulls in mater over it's Event Horizon towards it's Singularity. Does this have anything to do with Hawking's Paradox?

2007-12-18 05:56:46 · 3 answers · asked by Joehalfadolla 2 in Astronomy & Space

2007-12-18 05:56:41 · 3 answers · asked by Anonymous in Mathematics

2007-12-18 05:56:21 · 4 answers · asked by Anonymous in Mathematics

2007-12-18 05:54:17 · 20 answers · asked by Anonymous in Biology

Thats it !!

2007-12-18 05:54:08 · 7 answers · asked by stephensgaz 2 in Zoology

He is going 8 m/s on a straight plain when he comes to a hill. The hill is 6 meters tall. What is the velocity of the person and the bike when they reach the bottom of the hill. Don't take air resistance into consideration.

There isnt enough information to do the problem.
I dont understand how you are supposed to get the length of the hill (x) or the time it took to get down the hill.

Can someone help me?

2007-12-18 05:53:49 · 3 answers · asked by Derek S 1 in Physics

2007-12-18 05:51:34 · 9 answers · asked by kinder52438@sbcglobal.net 1 in Astronomy & Space

I am constructing a system using a standard Peltier component for use in a unique biomedical research application. I need to be able to seal the heat sink (cold side) of the Peltier component to improve its efficiency. The cold side will have a copper adaptor bonded to it and give rise to an insulated copper wire that pulls heat from the test system. I want to seal all the exposed copper on the cold side, so that only the wire insulation and sealant are exposed. The cold side of the component will be pulling about 0.5 W of Q and operating at about 5degC. The hot side will dump to forced convection and will not, obviously, be sealed. The sealant should be nontoxic, inexpensive, widely available, relatively easy to work with, and, above all, a good electrical and thermal insulator. It looks like the thermal conductivity of silicone and most epoxies are too high for my purposes. This is a little outside my area of expertise. Any suggestions?

2007-12-18 05:43:19 · 7 answers · asked by Sullydog 2 in Engineering

In total the jars contain 21 liter of wine. Each dwarf in turn gives all his wine to the others in equal shares. At the end of the process each dwarf has the same amount of wine as at the start. What was that?

2007-12-18 05:41:33 · 7 answers · asked by Anonymous in Mathematics

i know that a trillion miles is 1/6 of the distance light can travel in a year. But we clearly don't have any rockets that can travel 300,000km per second...so with what we do have right now, how long will it take for a spaceship (carrying humans) to travel a trillion miles?

(i'm unaware of the fastest spaceship unavailable at the moment)

2007-12-18 05:41:04 · 9 answers · asked by How To Save A Life 2 in Astronomy & Space

2007-12-18 05:32:42 · 5 answers · asked by Flor de liz C 1 in Astronomy & Space

If the sun moves 6 degrees in the sky, how many full disks of the sun would it move?

e.g. this is 4

_______
O
O
O
O_______

(I worked it out to be 7, but I'm not sure.)

2007-12-18 05:32:24 · 4 answers · asked by SteveLaw 4 in Astronomy & Space

It's Vout/ Vin or something, but i'm not completely sure... Help!

2007-12-18 05:31:58 · 1 answers · asked by sambrown2k6 1 in Physics

how do you do these two problems?

http://img161.imageshack.us/img161/9243/loln00bux5.png

please give an explanation, not just the answer. but an answer would be good too!

2007-12-18 05:30:58 · 4 answers · asked by Anonymous in Mathematics

2007-12-18 05:29:17 · 1 answers · asked by TL 1 in Chemistry

2007-12-18 05:28:29 · 4 answers · asked by TL 1 in Chemistry