Mystery Definition and 872 Threads

Did you know... ...that a comet's tail doesn't indicate the direction in which the comet is flying? I didn't, but having come across "Deep Impact" on TV yesterday made me wonder how a comet could have a tail formed from its coma when there is no friction to extend the dust to such a tail. And...

Homework Statement can someone please tell me why maple says that x=root(x^2+1)/x=.5root(2+root(20))?? ive tried trig and rearranging, but i have idea why this is so..

Homework Statement On May 19, an accident occurred at the corner of two asphalt streets with no stop signs. The speed limit was 40 km/h on both streets. As lead CSI on the case, you must determine whether one or both cars should be ticketed for speeding, which car had right of way at the...

I've been throwing this term energy around for a while now, and thinking about it I have absolutely no idea what it is. Is it something that actually exists in the universe, or just a construct that we use to simplify problems? Terms like kinetic energy, and even gravitational potential...

Lost please help! A 1974 kg weather rocket is launched straight up. The rocket motor provides a constant acceleration for 20.27 s, then the motor stops. The rocket altitude 23.94 s after launch is 7242. You can ignore any effects of air resistance. What was the rocket's acceleration during...

What leads us to believe that there is a black hole in the center of the milky way? If there is one, why is the center of galaxies always depicted as being a bright sphere? Is it a rotating black hole, and how would've it formed?

The Story It was 1st October, Matt, Cherry, and the 2 new detective girls, Amanda and Sylvia from Redrum University decided to give them a break from all kind of murder cases happened around them. Sylvia suggested they have a vacation at a beach which is not far away from where their...

Hi, The volume of a cone is 1/3 pi R^2 h. Why then is the answer in units cubed. Certainly the h is contributing a third dimension but in general math you don't see this happening X^2 * Z = X^3 but the below is true X^2 * X = X^3 Can a radius be multiplied by a height to make the...

I was browsing a hobby supplies site, and I came across retract servos. What are they? I know what a servo is, but I can't seem to find the definition of a retract servo. I've been searching for a while, and I'm sure it's there just staring back at me from the computer screen, but I'm not...

http://www.msnbc.msn.com/id/30353034/

I am wondering why a shower curtain is pulled inward when you turn on the shower. Yes, I have read the classic answer that this is due to Bernoulli's law: the water makes the air move, and moving air has a lower pressure. Only, this does not make any sense at all if you know anything about...

Why does the wind blow off the ocean during the day at the beach, and off the land during the night?

if, a particular body rotates ,with a certain velocity then every particle of that moves with the same velocity as that of body.if the Earth is moving at a velocity,we also move with same velocity daily . for eg:the speed of light was discovered to be 3x10^8m/s wrt to earth,but is it the...

Why there can exist some particles having spin = 1/2? I understand, the positive numbers but what do the negative number mean? Also, I would like to ask why some photons can be detected when it comes to light, but photon is not detected when it comes to charge replusion? What is the...

The UNH Physics Library has equations carved here and there on its walls. So far I recognize every one I've seen except this one: S = \frac {-1}{2 \pi \alpha ' } \int d \tau d \sigma \sqrt { -det (\frac {\partial X ^m}{\partial a} \frac {\partial X_m}{\partial b} ) } The...

let me see if I got this one right: By solving the S E for bound system u got the quantum number n l and ml. each set of numbers corresponds to a curtain wave function and electron. One gots fine structure when adding the spin up 1/2 and down 1/2. so every electron in the atom has a set of...

After reading a few books on relativity, I came to the conclusion that space and time are "somethings". And that if you removed all matter and energy from the universe space and time, or spacetime, would still remain. Perhaps I missed something, but in my history book at school I found in a...

Can anyone explain this "self healing" mystery. Can anyone think of any type of failure mode in an electronic component that could account for the following weird case of my self healing LCD monitor. ---------------------------------------- I've got this LCD monitor that's got a weird...

This problem has always bugged me, and the only answers I've been given were on the lines of "meh". What I don't understand is that if we are given 1 gram of a radioactive substance with a half life of n years, why is it that after n years, the substance is reduced to 0.5 grams of radioactive...

Hi there, I'm a lay person and would appreciate if anyone could point me in the direction of a good theoretical explanation of the neutron. All I can remember from high school physics is an explanation that went something like:- "Uh, well it doesn't actually do anything, it's just there do make...

Homework Statement A satellite is in an elliptical orbit at altitudes ranging from 230 to 890 km. At the high point it's moving at 7.23 km/s. How fast is it moving at the low point? I would think i would have to use some sort of energy conservation equations. but i really don't know where...

I'm doing an experiment of the Bohr's theory and the Rydberg constant. I want to find the element of a mystery gas using the derivation of the Bohr's theory: 1/λ=RZ^2 (1/〖n_i〗^2 -1/〖n_f〗^2 ) I think if I have the wavelength lambda, all I need to do is guessing a right series of n_i and n_f...

Hey everyone, I was tinkering with a battery, wire and such earlier, and I discovered something odd. :bugeye: I had a steel? wire and I placed the ends onto the terminals of a D battery for a time, and obviously, it warmed up. But I also had a thing that played a recorded music track when two...

Hi all, there is something I cannot completely understand about the Schroedinger equation for a charged particle in a constant magnetic field. I think I get most of it, hopefully, but there is something I still am unable to fit into place. So we know that when a magnetic field is present...

Our solar system is often depicted, as it is on the poster on my wall, as the Sun and all of its satellites in coplanar orbits around it. I thought, however, that this "flat" representation was just a creative liberty taken to make is possible to put on a poster, but now I come to find out that...

Would Dark matter form out of the primordial plasma at the same time as baryonic matter, did some thing special happen to form this weakly interacting particle?

Homework Statement I feel silly posting such a simple problem, but a substantial amount of thinking, Googling, and scouring these forums has not yielded an answer. Homework Equations Newton's Second Law: F*_net = ma* (where the asterisk denotes a vector quantity) Newton's Third Law...

Hammer Rotation Mystery.? Hi... Below is a link that shows a blond Russian lady Hammer thrower (ther are about 4 other people befor the video gets to the blond Russian lady) which includes slow motion video of when her hammer hits the ground.! in the video of the Russian lady...

Homework Statement Explain why large sparks are often seen jumping from leather belts driving machinery. Homework Equations The Attempt at a Solution I know metal chains are off trucks to stop electric static but I'm not sure why leather. Is leather a conductor?

I have a strange mystery. My house sings! I am wondering if anyone can take a guess at what could cause this. I have occasional insomnia, which leaves me lying there in bed in the wee hours of the night when it is dead silent. Well, this morning was one of those. I woke up around 1:00 am...

Homework Statement A batted baseball leaves the bat at an angle of 33.0 above the horizontal and is caught by an outfielder 400 ft from home plate at the same height from which it left the bat What was the initial speed of the ball? How high does the ball rise above the point where it...

Homework Statement A passenger in a helicopter traveling upwards at 17m/s accidentally drops a package out the window. a)If it takes 13s to reach the ground, how high to the nearest meter was the helicopter when the package was dropped? b)what was the maximum height of the package above the...

http://www.msnbc.msn.com/id/28622042/

Irene Klotz, Discovery News, 12th Jan 09- http://dsc.discovery.com/news/2009/01/12/strange-light-hubble.html and from the Hubble site- http://hubblesite.org/newscenter/archive/releases/2009/04/

how come some computer parts double they're power once in like 18 months or so? it's kind of weird...alwais +100% and in 18 months or so...for example take the RAM memory...they came like this(in MB): 8,16,32,64,128,256,512,1024,2048,4096,8192! I didn't cheked,but the 16 GB RAM stick might be...

Just found this article...thought you guys may want to check it out. http://www.space.com/scienceastronomy/090107-aas-loud-cosmic-noise.html

Hello to all! I have but 1 simple question: Has the secret of Nikola Tesla's ability to run a car on power from "the ethos" ever been revealed? Was it a permanent magnet motor the didn't need an external power source? I can see all the skeptics eyebrows being raised as we speak regarding...

Hi all :D, I was wondering if someone could help me. My physics teacher once told me about this unsolved mystery - and I have a vague memory of it. I was hoping someone could help me find out what it is. Basically it was something to do with astronomy and about a Greek astronomer. I...

Homework Statement The following five points lie on a function: (1,20) (2,4) (5,3) (6,2) (10,1) Find an equation that passes through these points and has these features: a. There are three inflection points b. There is at least one local maximum c. there is at least one local...

What is the explanation for the tide on the surface of the Earth opposite the moon?

Can anybody explain why my numbers are not equally out? At work, I am trying to determine the heat transfer taking place in a water cabinet. Both loops have water in them. There is a counter current flow heat exchanger where the transfer takes place. I take the temperature measurements...

I don't understand what really is happening. When there is fog on the (inside)windshield of my car, I turn on the AC and it goes away. Are the water droplets freezing? Am I changing the dew point? Why does it go away? If I leave the temperature at 62F, the fog increases. Can somebody...

If someone dies in a hospital a member of medical staff tries to brings their heart back to life, sometimes this works. Why if someone dies of nateral causes can't their heart be braught back to life after a while?

I was going to have baked potatoes for lunch so i put them in the oven on high, half an hour later the houses filled with smoke, it is still lingering now, what ever had spilled over in the oven previously must have burnt and burnt and burnt, strange as the last thing i baked did not cause any...

I was looking at my periodic table in Chemistry today and noticed that Chlorine's relative mass was 35.5, how can it have half an amu when it has 17 electrons? That's not 0.5amu, is it?

I was out for a wander yesterday when I stumbled across a little run-down hut with 3 walls and no door. Inside was a table, 3 chairs, remnants of some candles and a pile of poppy seed heads. Written in pencil all over the table was some notation. It was mainly numbers set out in rows, arranged...

I love Gizmag, and they've presented a challenge. (Actually, Honda presented it; Gizmag is passing it on.) The link shows a Honda concept bike that appears to have no tires, suspension, or drive train. I can think of a few ways that the suspension, steering, and power system might be done...

I'm trying to figure out where I'm getting these bites from. Skeets or fleas or whatever. I've got about six bites in the soft crook behind my left knee. None behind the right knee. They are very itchy. They have been occurring over at least a week or more. Still occurring, in fact. I've...

1. Why does a crate on an accelerating truck accelerate backwards proportional to the amount of kinetic friction? I don't understand why the crate accelerates backwards as if kinetic friction was the only force acting on it. 2. Homework Equations : F=ma

Homework Statement http://img159.imageshack.us/img159/1867/es100wi8.th.png http://g.imageshack.us/thpix.php a) Write an expression for V1 and V2 both in time domain and phasor domain (Solved) b) Write an expression for the current I both in time domain and phasor domain (Solved) c) Calculate...