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Physics - March 2007

[Selected]: All categories Science & Mathematics Physics

If u had a cloak that made u invisible, like in harry potter, where would u go , or what would u do with it?

2007-03-20 06:59:09 · 6 answers · asked by hot_rican_4_ju 3

The wavelength of the emission maximum from a small pinhole in an electrically heated container was determined at a series of temperatires, and the resuilts are given. How to deduce a value for Planck's constant?

2007-03-20 06:49:07 · 3 answers · asked by jenny w 1

If so, where can I buy 130 V lightbulbs?

2007-03-20 06:45:58 · 7 answers · asked by Sticky-1 1

Oliver (m=74.9 kg) uses a 4.26 m long rope to pull Jordan (m=51.7 kg) across the floor (μk=0.200) at a constant speed of 1.72 m/s. Jordan signals to Oliver to stop by "plucking" the rope, sending a wave pulse forward along the rope. The pulse reaches Oliver 136.0 ms later. What is the mass of the rope?

2007-03-20 06:36:49 · 1 answers · asked by N 1

I have a couple of questions about the book "A Short History Of Nearly Everything" by Bill Bryson.

1. In the book it says that proof of the Big Bang is the fact that something came from nothing. I agree that there is obviously "something" now (the universe), but how can you say that it was nothing before and that all that is a "fact"?

2. And has there ever been an occurance in science, in perhaps a smaller size (so that we could have witnessed it with our own eyes) that had similarities to the Big Bang theory? Or is the creation of the universe the only place that anything even remotely similar to the Big Bang theory has ever happened?

3. If i understand correctly, Singularity has no dimensions, right? Ok but then...what exactly does it look like, if it has not even a 2 dimensional size? Doesnt even the most thinnest line have 2 dimensions?

2007-03-20 06:33:11 · 4 answers · asked by Jaded 7

Just curious if there could be some physics to explain why signs can sometimes be so compelling and relevant for those that fall under their respective ones?

2007-03-20 06:24:16 · 4 answers · asked by Bumbo 3

What possible practicality could this E8 hold and what prompted the original person over a century ago to look around for something so abstract and irrelevant?

2007-03-20 06:18:26 · 2 answers · asked by Bumbo 3

2007-03-20 06:07:51 · 7 answers · asked by jojo 1

I am aware that the less surface contact the less friction, but how does soap reduce surface contact.

2007-03-20 05:55:54 · 2 answers · asked by Anonymous

2007-03-20 05:38:35 · 1 answers · asked by wendy k 1

The square root of gravity at sea level (9.81) is 3.132092.
Pi (3.1415927...) squared is 9.8696044
sometimes in equations, you can cancel the square root of gravity with pi.
My question is, at what elevation above or below sea level is the gravitational acceleration equal to pi squared?

2007-03-20 05:30:04 · 4 answers · asked by Anonymous

can you help me please.
20 m/s
40 m/s
60 m/s
None of these

2007-03-20 05:01:57 · 7 answers · asked by Sesily E 1

Hi, Dear All,
Do electrons travel as waves? The answer is NO. De Broglie wavelength only true when electrons move at low velocity. but at high velocity and high energy, De Broglie wavelength fails but adhere to special relativity principle. I have found out the reason and prove that electrons do not travel as waves. Please browse the link below for more detail,
www.greatians.com/physics.htm
More interesting stuffs about physics are shared too. Have fun and enjoy. Thank you.

2007-03-20 04:54:23 · 6 answers · asked by kongkokhaw 1

Can someone help me with this problem? You do not need to do them just give me some hints on how to do it, thanks in advance

During a head-on collision, a passenger in the front seat of a car accelerates from 13.3 m/s ( 30 miles/hour) to rest in 0.10 s.

a. Calculate the acceleration of the passenger.

b. The driver of the car holds out his arm to keep his 25 kg child (who is not wearing a seat belt) from smashing into the dashboard. How much force must he exert on the child?

c. What is the weight of the child?

d. Convert the forces in parts b) and c) from Newtons to pounds. 1 lb = 4.45N. What are the chances the driver will be able to stop the child?

2007-03-20 04:37:05 · 4 answers · asked by abxamz 1

A parallel-plate capacitor consists of two parallel circular
plates separated by distance d, d is much smaller than
diameter of plates. Each plate has net charge zero.

What is potential energy of a point charge Q located
inside the capacitor at its center, d/2 from each plate,
with respect to infinity?

2007-03-20 04:36:36 · 3 answers · asked by Alexander 6

http://www.socratus.com
=================

2007-03-20 04:35:15 · 5 answers · asked by socratus 2

I know that the object (1) absorb all wavelengths and reflect the wavelength that we actually see. At the atomic level, I am told that (2) electrons are excited by the light and when the electrons returns to its original orbital. This gives off a wavelength. I am wondering how (1) is related to (2). i.e. How does the reflection and absorption of color wavelength work at the atomic level.

2007-03-20 03:54:56 · 2 answers · asked by Gordon F 2

Whenever you are calculating the currents in a circuit using Kirchhoff's rules, if you should calculate a negative value for a current, what does that mean?

2007-03-20 03:46:53 · 1 answers · asked by Chad B 1

2007-03-20 03:44:04 · 2 answers · asked by Krishna Adhikary 1

Model rocket engine are sized by thrust .... A rocket engine has an average thrust of 5.26N and mass of fuel 12.7g and initial mass of 25.5 g the duration of burn is 1.9 sec
a) What is the average exhaust speed of the engine ?
b) if the engine is place in a rocket body of mass 53.5g what is the fina velocity of the rocket if it is fired in outer space asume the fuel burns at a constant speed !! !
HEEEELLLLLPPPP !!!

2007-03-20 03:40:48 · 2 answers · asked by Anonymous

Electrons do not travel as waves. De Broglie wavelength does not prove that electrons travel as waves. For high velocity moving electrons, the De Broglie wavelength fails, but adhere to special relativity principle. Therefore, De Broglie is not appropriate to describe electrons travel as waves. However, to tackle this question, I had proven that electrons do not travel as waves, and able to point out the shortcomings of De Broglie wavelength. I am preparing a website soon to present my work. Please be patient. Thank you.

2007-03-20 03:30:36 · 4 answers · asked by kongkokhaw 1

I am in Ecuador, with American appliances. Current here is 110v like in the US. I don't know if I should use a surge protector or a voltage regulator. Electricity here goes on and off regularly and several people have had small heating appliances (coffee makers, hair dryers, etc.) break down... I have an expensive espresso machine and would die if it broke down!

2007-03-20 03:30:06 · 3 answers · asked by cant figure it out 3

These are the choices I have to chose from?
truck
bicycle
neither
they have the same momentum

Can you please help me?

2007-03-20 03:28:44 · 6 answers · asked by Sesily E 1

2007-03-20 03:16:11 · 2 answers · asked by cove128 1

A high speed train is moving & its height is twice that of its length.A ball is thrown in upward direction & it came back to the ground.Where will the ball land on the ground?
The ball didn't touched the roof but it was just a micrometer away from the roof of the train during its returning journey.

2007-03-20 03:10:36 · 9 answers · asked by rajesh bhowmick 2

http://www.centauri-dreams.org/?p=976

Think this guy is legit? Think GOOGLE should fund him? Think GOOGLE would be a good stock to buy, either way if it works or not?

2007-03-20 03:00:11 · 1 answers · asked by stargazergurl22 4

fedest.com, questions and answers