Physics

If a limiting friction of an object is 10N and the kinetic friction is 5 N. If I apply a force of 20 N continuosly would I be accelerating with a 5 N force forever.

my friend said..In physics, acceleration does not mean speeding up. right? also, why any change in velocity is called an acceleration.. deceleration is a decrease in speed...why deceleration is not much used? thanks

I specifically need the heat capacity of ethanol/water mixtures at various temperatures and pressures (all concentrations, from room temperature up to >200 deg C)... I'd like to learn how to calculate this myself but "Excess properties" (like the Excess Gibbs energy and excess enthalpy that you find in the thermodynamics textbooks give me a headache). In addition, I have a feeling that the beautiful thermodynamics theories are not of much use because the ethanol/water system is highly non-ideal (but I might be wrong here). Does anyone simply have a source (books are also fine - just tell me the title + author/editor) where stuff like this is listed? I'd r…

1-A jogger travels from x=0 to x=50 m between t=0 and t=10 s.Between t=10 s and t=15 s, the jogger travels from x=50 m to x =25 m. Is the distance traveled by the jogger equal to the magnitude of his displacement (a)between t=0 and t=10 s. (b)=between t=10 and t=15 s?Explain..

Hello everyone, How does an electric field create a magnetic field. If we move at the same speed in the direction of the electric field would we see a magnetic field. Would we still see it because it is perpendicular but we would see the electric field not moving so not sure. Thanks!!

Hello, Quick question. This is a light wave This is another light wave Why doesn't this graph have another perpendicular graph. Are they talking about the particles in the magnetic field or electric field here or both. Simply how do they make one wave out of a light wave that has two waves

According to Wikipedia, a field emission display (FED) is a next-generation flat panel display technology that uses large-area field electron sources to provide electrons that strike colored phosphor to produce a color image. An FED display replaces the single electron gun of a conventional CRT with a grid of individual nanoscopic electron guns. The emitters were originally built out of tiny molybdenum cones known as Spindt tips, but most recent FED research has focused on using carbon nanotubes instead. A high voltage-gradient field is created between the emitters and a fine metal mesh suspended just above them, which pulls electrons off the tips of the emitters. Th…

I was reading up on cryogenic systems in the Large Hadron Collider and they mention a 'white book', also called The Large Hadron Collider Accelerator Project, eds. Y. Baconnier, G. Brianti, Ph. Lebrun, A. Mathewson and R. Perin, CERN/AC/93-03 (LHC) Report (1993). The problem is I looked everywhere on the net and couldn't find this report. Do you know where I can find it?

How do I calculate the 'potential?' resistance in a tube, in cm H2O. I'm a physiotherapist and do positive expiratory pressure breathing exercises with lung patients. Problem, the PEP masks are quite expensive, so we make 'blow bottles' - simply a 1 litre bottle, half filled with water (about 10 cm), with a nice thick (about 1 cm diameter) silicone tubing of about 20 cm, through which the patient blows into the water to make it bubble. Another problem - blowing into the water retains the lung pathogens in the water where they can proliferate. I'd like to use the straw as it is to avoid a contamination source, but would like to know what resistance it will give during exp…

Hi: I have some questions regarding flames. A dicyanoacetylene-ozone flame reaches a temperature of 5516 K. This causes it to emit EM radiation mostly in the UV spectrum. A wooden log flame reaches only 1170 K, as a result it emits most of its EM radiation in the IR spectrum. Since IR generates more heat on human skin than UV of the same intensity, does this mean that a wood log flame will be perceived to be emitting more radiant heat than a dicyanoacetylene-ozone flame? Also, does a yellow bituminous coal flame give off more infrared radiant heat than a blue methane flame? My guess is yes, because the former gives off light due to incandescence [about 90% of …

Millions of Piezo sounder material manufactured in very long strips, attach both ends to poles, upright in the sea to generate electricity using the waves. Or some sort of mechanical wave blanket in layers through the sea. Or simply a millions of water wheels. Merged post follows: Consecutive posts mergedFound a patent "Piezoelectric generation of electrical power from surface waves on bodies of water using suspended weighted members" http://www.freepatentsonline.com/5578889.html That patant differs from my invention as I wish to use undercurrent or surface waves if I can get cerramics to vibrate using metal or other. This is getting alkward as I coul…

is there such thing as zero gravity?

DO NOT CLOSE THIS TOPIC WITHOUT DISCUSSION! IF YOU THINK SCIENE IS RELIGION THAN I BETTER FIND ANOTHER FORUM AND I WILL BLAME THIS SITE FOREVER. http://knol.google.com/k/alex-belov/paradox-of-classical-mechanics-2/1xmqm1l0s4ys/9# The experiment_2 animations This is animation based on classical mechnics laws This is animation based on theory of standalone rotation with translation movement. The Natural Experiment 2. I made 3 successful experiments with 2 pencils. On all these experiments pencils with rotation movement have lower velocity than pencils without rotation. The theory is CORRECT. Th…

why are all the protons in the middle with the electrons moving around them?

Does anybody know of a site (not Wiki, tried that) that gives a comprehensive explanation and solution(s) to the (gravitational) two body problem? Because all the sites so far I've seen are more or less a copy of the Wikipedia article. Thanks

Can you hold back a car? no can you pick up a car's petrol tank full of fuel? yes billions of years of energy! And almost halfed the worlds polution levels!!

Out of curiosity, is it theoretically possible to extract electrons from metals, perhaps through the administration of strong magnetic fields? If so, could this, hypothetically, be used as an energy source, or would whatever energy it would yield be equal to the energy it would cost? I do realize that it would be impossible to gain a net energy from the electromagnetic force of the electrons, since whatever energy that might produce would be exactly equal to the energy it would take to extract the electrons from the metal. Metals are, after all, generally electrically neutral. What I was wondering, however, was rather if it would be possible to use the kinetic en…

http://knol.google.com/k/alex-belov/paradox-of-classical-mechanics-2/1xmqm1l0s4ys/9# Animated experiment 2 This is animation based on classical mechnics laws This is animation based on theory of standalon rotation with translation movement. The Nature Experiment 2. I made 3 successful experiments with 2 pencils. All these experiment shows different velocities between pencils. The theory is CORRECT. The simulator is WRONG. Here is some snapshots from experiment, which shows experiment dynamic. Links to experiments movies (avi files) Experiment 2_1 Experiment 2_2 …

------> Boat going at 10m/s ------> Sea going at 5m/s What is boats speed relative to the sea. If I use vectors it would BS= BG+GB =15-5=10m/s But the answer must be five and BG=15m/s(A person in the ground would see the boat travelling at 15m/s) Where have I gone wrong?

My class has spent several weeks on making a student designed practical experiment and unfortunately due to illness I have been away. Does anyone know of any good experiments that can be conducted in a classroom involving motion, particularly to prove the effect of safety features in cars? Or if not this, than just of any experiments involving motion? I haven't started at all and can't think of anything (complete mental blank), it seems as though physics is too demanding of a subject and impossible to apply the theory to practicals. Well, is anyone willing to prove me wrong? Anyone have any ideas?

Nothing I do ever works. I made my solenoid type thing with about 300 turns, and Im using strong neodymium magnets... I get 0.02 volts when I pull the magnet out very fast... it is not enough. I want to make a series of these solenoids so when I move the magnet across I want to "feel" a drag, and I want to actually produce some electricity (it will be AC but it's okay). If I move the magnet at 20-30m/s I want to get at least a few volts. So what's the trick to making one of these generators? Am I building it wrong? What sort of resistors can I hook up so that I feel it hard in my hand to swipe the magnet across the top or the solenoids?

http://www.scienceforums.net/forum/showthread.php?t=43217&page=2 ^How do you explain Baseballs, Tennis Balls not applying a force on the sweetspot with Physics?

I have a bunch of pseudo-designs drawn up (ie. not very specific, definitely not professional) for ideas of what to do with lightning. Most of them revolve around the idea that I can attract lightning with a tall enough stack of aluminum cans. This stack would ideally be set up away from buildings and trees, and would be set up when there isn't a cloud in the sky. (Or at least not directly overhead) In order to make the stack stand up without breaking, I'd probably need some strong adhesive, one that either doesn't set fire or does conduct electricity (or at least, conducts electricity without setting fire) and I'm not sure if superglues I'd find at hardware stores wo…

When we see the color green (green is 490 nm - 560 nm on the electromagnetic spectrum), is it many electromagnetic waves or only one wave?

If one has a very long stick, say 1 light year long that is not compressible and one moves it through space. Ignoring inertial problems isn't one sending data from one side of the stick to an observer at the other at a speed faster than light. Discuss.