Physics - January 2007

working between an upper temperature at 400 C and a lower temperature at 18 C?

2007-01-19 12:28:55 · 2 answers · asked by zizi m 1

Ok, i know everything about charged particles attracting if they're opposites, but if earth is neutral, what provides the force to pull the neutrons from the clouds(negative cahrge) to earth and create lightnign?

Is the answer polarization? im kinda confused help plz

2007-01-19 12:13:24 · 14 answers · asked by Anonymous

When goofing around with a magnet, one will find that some small stuff (with some Fe in it) will become magnetized (to whatever degree).

What would be required to magnetize something of pretty substantial size - like a fire hydrant or a manhole cover or the side of a car ?

All kinds of stuff could be magnetized - just for laughs - if it's practical to do so. (I don't need admonitions about the potential damage/problems that magnets can cause).

And would it stay magnetized ?

2007-01-19 12:08:16 · 2 answers · asked by roland_reardon 2

at 20 C from 1 to .3 atmosphere of pressure.

2007-01-19 11:46:20 · 1 answers · asked by Anonymous

2007-01-19 11:41:20 · 3 answers · asked by Anonymous

If you know the science in using the structure of a golf club tell me all about it?

2007-01-19 11:31:27 · 1 answers · asked by stusa 1

I am stuck on this problem and wondering if someone could offer some assistance. How does one find the individual values for Vb, Va, etc. without any given point charges. I've been using the equation delta(V)=-Ed and using that equation I was able to get A correct. It's not working for B and C though. I'm not sure how to determine the different potentials when I have no values for the point charges. Can anyone offer some assistance? I've been working on this problem for the better part of the last two days and I'm quite frustrated

The drawing shows a uniform electric field that points in the negative y direction; the magnitude of the field is 1600 N/C.

http://www.webassign.net/CJ/p19-32.jpg

a) Determine the electric potential difference VB - VA between the points A and B.
The answer here is 0 V.

(b) Determine the electric potential difference VC - VB between the points B and C.
V

(c) Determine the electric potential difference VA - VC between the points C and A.
V

2007-01-19 10:51:53 · 3 answers · asked by larkinfan11 3

2007-01-19 10:49:00 · 11 answers · asked by chazzer 5

The second law of thermodynamics, like no other physical law, defines a direction of time. All other laws are time-reversal invariant, meaning they are valid despite which direction time flows. Why is this so? What does this say about time?

2007-01-19 10:40:04 · 3 answers · asked by Anonymous

some of my students are working with phosphorescent paper. They are looking for any object the "appears invisible" by being clear, yet still blocks the light? They want to put the object on the paper so that a person a few feet away can't see it, but when the phospor paper is hit by the light, the shadow of the object apears.

I think it's a very cool idea, but I also a think it's a real long shot. I really need some help from you science geniuses that hang out here.

2007-01-19 10:20:12 · 6 answers · asked by Anonymous

Ignoring how long it takes initially to heat the house to 70 or 80 degrees, maintaining the temperature once it's there should take the same amount of heating. Yes or no? IE, heating the house from 69 to 70 degrees takes the same amount of energy to go from 79 to 80?

2007-01-19 10:15:02 · 12 answers · asked by Paper M 1

I cannot find any way to solve this and am in some desperate need of help. Anyone?

One particle has a mass of 3.00x10^-3 kg and a charge of +7.80 µC. A second particle has a mass of 6.00x10^-3 kg and the same charge. The two particles are initially held in place and then released. The particles fly apart, and when the separation between them is 0.100 m, the speed of the 3.00x10^-3 kg particle is 125 m/s. Find the initial separation between the particles.

2007-01-19 09:22:02 · 2 answers · asked by larkinfan11 3

ice melting
ice being carved
water boiling
water breaking down into hydrogen and oxygen

2007-01-19 08:59:46 · 4 answers · asked by aestheticxxlove 1

I've written a program to rotate objects in 3D. It works good. I could never quite get my head around 3D rotation though. So I figured out 2D first:
1) Start with a point, X,Y
2) Find the angle using ATAN
3) Rotate the angle whatever
4) Recalc and redraw X,Y
Works great

I got really confused when it came to 3D because of the more complex relationships between the different axes.

So I did this:
1) Start with X,Y,Z
2) Find angle for X,Y using ATAN
3) Rotate some
4) Recalc X,Y
5) Find angle for Y,Z
6) Rotate
7) Recalc Y,Z
8) Find angle for X,Z
9) Rotate
10) Recalc and redraw X,Y,Z

I probably did more steps here than I needed, but I had to keep the axes separate so I could visually comprehend what I was doing. Can anyone explain 3D relationships clearly and how the angles/sines/cosines/tangents are related. Can this be done more simply and please explain why.

Also, is there a way to rotate 2D and 3D cartesian coordinates without finding the angles?
Thanks

2007-01-19 08:56:49 · 2 answers · asked by ExcelerNot 2

2007-01-19 08:56:44 · 2 answers · asked by jarynth 2

2007-01-19 08:42:35 · 12 answers · asked by damigurl05 1

2007-01-19 07:49:54 · 7 answers · asked by Anonymous

Hi im currently studying A-level physics and am having trouble understanding the concepts of these diagrams. I get really confused, and all i can remember is that there must be equal and opposite forces using Newton 3.

2007-01-19 07:35:54 · 4 answers · asked by matt v 1

2007-01-19 07:34:00 · 4 answers · asked by booger 2

2007-01-19 07:29:25 · 20 answers · asked by nick 2

Heard this the other day and is quite scary, would that mean tide changes will occur and also that maybe the pull of the moon will halt the tide process so the seas will become stagnant???

2007-01-19 07:00:25 · 6 answers · asked by Anonymous

The speed of an object and the direction in which it moves constitute a vector quantity known as the velocity. An ostrich is running at a speed of 25.6 m/s in a direction of 80° north of west. Please explain how you get the answer.

(a) What is the magnitude of the ostrich's velocity component that is directed due north? (answer in m/s)

(b) What is the magnitude of the ostrich's velocity component that is directed due west? (answer in m/s)

2007-01-19 06:58:46 · 3 answers · asked by mariah3785 1

Say you stick your arm out the window of an airplane in the winter time. At certain speeds your arm will get colder faster from the wind chill. But at what speed of the airplane will the air moving across your arm actually begin to warm your arm?

2007-01-19 06:33:01 · 1 answers · asked by Jason 1

i know that when the light intensity of a light source falling on an LDR is high, the resistance in the LDR falls and when the light intensity is low, the resistance of the LDR is high.
and i know that when resistance is high, current flowing through the LDR is low and vice versa.
however, whats the relationship between the voltage and the current in an LDR? are they directly or inversely proportional?
if the current in an LDR rises, will the potential difference also rise or fall?
this is quite important as i need it for this sensor i'm making at school.
if u've got ur information from a website, could you also mention the website here or create a link?
thanks

2007-01-19 06:08:36 · 3 answers · asked by amandac 3

Hi,
I do Physics (GSE level only) and am interested in knowing what Einsteins Theory of Relativity is in simple terms.

I just want to know what he has said, how it helps us, and what does this mean about time stopping ... .

Thanks, remember in Physics terms, but relatively simple as I am not doing higher physics yet.

Thumbs up... for all you answers, and thanks!

2007-01-19 05:56:59 · 6 answers · asked by ღ♥ღ latoya 4

The delivery of mass in a precise unit of time & location related to the acceleration of light & the laws of the universe. I'll explain E 5 equivelent to V 5 = V 22 C 3 (see 3) C2 a factor of one or 1/27 the sum of two add S for more than one 19 54 a factor sum of 2 or note 12/27/1954 V M 22+13 ='s 19:35 or V 2 times V5+2=7:35pm spher location longitude M one's three or III.sum 54' C 2 numerical charactors exprss as 00" that doubles express as "w" so the complet answer is 12/27/1954 @7:35pm or Navy time 19:35 on longitude III.54'00"w
So where is my monetary gifts associated with my academic achievement the delivery of mass threw time express as E=mc2 ?

2007-01-19 05:34:33 · 7 answers · asked by Anonymous

i the hollywood films and series we see space travel and intergalastic travels. But how can we communicate with other stations which are light-years appart without much delay while any kind of radiation can have atmost the speed of light?

2007-01-19 05:01:23 · 11 answers · asked by Aaron J 1

how do you calculate this problem?

volume=4/3pi r3 use 3.14 for pi

diameter is 4.2 mass is 18.6

2007-01-19 04:48:55 · 7 answers · asked by missy 1

Can a different approach make a better country?

2007-01-19 04:44:04 · 19 answers · asked by 1978nevaeh 3

2007-01-19 04:17:52 · 3 answers · asked by rutgersfootball06 1