Head Definition and 391 Threads

Just a simple question: Does a fly that buzz around your head while you travel on an open boat (with some sort of wind screen in front) move relevant to you, and therefore travel at higher speed with no more effort than it would if your boat stood still?

A B --> <-- 24kgm/s 10kgm/s Two trucks A and B are about to collide head on; their values of linear momentum are as shown in the figure above. After the collision the two trucks separate and move away from each other, at which time truck A has a linear momentum...

Hi. I'm trying to determine the flow rates of water in a pipe network. At a junction in a pipe, for example a simple y junction where the water heads out of a tap down a short length of tube before splitting into two lengths of tube of the same diameter, would the head loss equation for one of...

For a while now, id say a matter of months that i can remember, i will say the number 20 or 27 in my head. I never mean to or plan to, but i still do from time to time. It hasnt happened lately, but its very strange. I will be walking from class to my apartment and talking to myself in my head...

Belongs in a 'nature' forum, but this is as close as it gets. Why do some birds (pigeons, starlings) bob their heads (front and back) when they walk? I have two hypotheses: 1] They have lower retinal retentiveness, and must hold an image on their eye longer to resolve it. They move their...

So my physics class is studying sounds and light waves right now. We were discussing how different things affect the sound waves. My question relating to biology is this: my mother and sister and I sound very much alike...except that they tell me my voice sounds as though it is a lower pitch...

What are some good quick ways to Extract Square Roots in your head. I'm looking for a method that is very prescice and easy thanks, hopefully somebody helps me out

Given: Two gliders on an air track collide. Glider A has a mass of 0.269 kg and is moving in the +x direction with a speed of 1.07 m/s. Glider B has a mass of 0.330 kg and is moving in the -x direction with a speed of 0.675 m/s. a) What is the velocity of A and B if the collision is...

Can anyone help me with this problem? Two billiard balls of equal mass undergo a perfectly elastic head-on collision. If one ball (ball A) is initially moving at 1.9 m/s in the +x direction, and the other (ball B) is initially moving at 3.9 m/s in the -x direction, what will be the...

hey guys, i need help on my integral calculus hw 2) int(x*3*e^(x^7)) dx this one is just giving me insane problems

Lost in this review problem: Most of us know intuitively that in a head-on collision between a large dump truck and a subcompact car, you are better off being in the truck than in the car. Why is this? Many people imagine that the collision force exerted on the car is much greater than that...

I want to share and discuss with every forum posters here a new concept on piston heads, which by the way is not as brainy as you may think. The new concept is concerned with spark ignition engines. Everybody know that combustion process have two main stages in this kind of engines...

:confused: PLEASE HELP WITH FOLLOWING PROBLEMS ATTACHED WITH THIS ? :cry:

what does a head on collision imply? does it mean that the photon will be bounced back 180 degrees ?? If this is the case we now know where the position of the electron in the atom, but the momentum is uncertain because it had some 'inital' momentum right??

Not only Gandalf loses his patience with this obnoxious fellow; Dr Zhivago became equally irate (or at least, Peter O'Toole did) http://www.hindustantimes.com/news/7242_1088085,00180007.htm Any sympathy for John Noble here?

A 4.5 kg object with a speed of 4.0 m/s collides head-on with a 11 kg object moving toward it with a speed of 3.0 m/s. The 11 kg object stops dead after the collision. (a) What is the final speed of the 4.5 kg object? (b) Is the collision elastic? so i tried initial momentum = final...

Hello again all. This is my 6th posting requesting some assistance for some new physics problem. It is getting a bit easier to understand but I would like some review and comments on the following problems. My answers are marked with an astericks. You do not have to necessarily provide me...

Reduceing atmosphric pressure Six electrical contacts as small and as close as we can make them on a surface. Call them ABCDEF. Apply current to C&D electrons are separated from air molecules in contact with C&D. Apply a positive charge to A the electrons will be drawn to A across B. Apply a...

So what does a person, born deaf, sound like in his/her own head? I know what I sound like in my head. I wonder what these people sound like. Do they think in visual's? And if that's the case what does a Blind and Deaf person sound like or see like in his/her head? :smile:

Ok I have the following question: If the top of your head has a surface area of 113 cm2, what is the weight of the air above your head? I'm not sure what I am doing wrong. I used the P = F/A. Solved for F to get F= P/A. I'm assuming the question is asking me for the force of the air on my...

"Kerry Hits Nail on Head" Gosh! I'm just finding interesting stuff all OVER the place! :biggrin: Kerry Hits Nail on Head By Marjorie Cohn t r u t h o u t | Perspective Monday 04 October 2004 http://www.truthout.org/docs_04/100404A.shtml

Struck in head by rock! This past Sunday I was rock climbing in Eldorado Canyon, Colorado. Another climber was on a route just left of me and well above me. When he climbed up onto the belay ledge he accidentally knocked loose several rocks. One rock hit me in the head. Fortunately, I was...

A typical car with a dummy crashed into a wall, what is a suitable parameter for the head of the crash test dummy(with and without restraints) as a function of time? and how do i estimate the forces acting on the head in the two situations? Thanks a lot :confused:

Hi All, I wonder if you can help me with a little puzzle I'm working on. I'll include a picture for clarity. I suspect that you mathsy types will be able to tell me straight away if this is possible or not, but I just can see the obvious... I have a fine square grid of numbers (blue in...

http://www.wired.com/news/culture/0,1284,63278,00.html?tw=wn_tophead_1

Relativity has been so hard for me to understand! One minute, it makes sense, and the next I am lost. I kind of understand how time can go slower based on the view it is taken from, but I can't understand how a person could actually not get older? That is, if the person is going really fast...

Hi, Just out of curiosity. We all know that women have different nipple heads.(Actually guys do too). What is the key determinant here? From mom? Dad? And is there a majority kind of nipple head for different kind of people? I know asian girls tend to have "petite" nipples and most...

I'm just answering a thermodynamics problem of my Physics homework and I just can't get my head around it here. I'll give you the quesion here, and the reason I don't get it is because you're given the mass of the substamnce as opposed to the number of moles etc... The latent heat of...

Natural selection at work: Ku Klux Klan shoots itself in the head Duncan Campbell in Los Angeles Wednesday November 26, 2003 The Guardian The Ku Klux Klan, the white supremacy group notorious for its lynchings of black people and those who favoured desegregation, has scored a...

I need to know where to start, any good books to help out I'm taking a self study course. I have some study guide from Army education center. I am waiting for video course show up. How long would it take for an object dropped from the Leaning Tower of Pisa height 54.6 meters to hit the...

An alternator attached to a water turbine generates 35 Watts given 50 feet of head and 10 gallons per minute. Assuming that the efficiency of the alternator is 50%, is it possible for me to find the angular velocity from this information? If so, how would I do it?

How to tell if your head is about to explode...? http://www.mit.edu/~mkgray/head-explode.html Interesting. Can someone just validate this for me from a second news source. Just so I know this isn't a big joke.

Please see the thread: https://www.physicsforums.com/showthread.php?s=&threadid=7946

Okay guys get this. So there are these two or three kids at school that seem to think they're so intimidating (they might be for some people) that like to pick on me and sometimes a friend of mine also. They're your typical bullies, ugly hair, earings, and one that always wheres a leather...

I saw a program about two serious studies done to test the notion that people can tell when someone is behind them looking at them. One study was conducted by a woman who explained to the volunteers that the point of the study was to show there was something to it. The other study was conducted...

I think you may be the first person to accuse the UFO crowd of lacking creativity. http://www.abduct.com/question/q186.htm http://www.syndicate23.com/index.cfm/resource_id/107.htm http://library.thinkquest.org/C004978F/ufo_aliens.htm?tqskip1=1&tqtime=1019 This is me: Now don't...

The question asked me to find the head of a vector [a,b,c] whose length is 3 and is in the same direction as vector a=[-3,-4,12] So I found the follwing: Let vector x be the unknown vector |a|=13 |x|=3 Since they are both in the same direction, they both must have the same...

Here is a true story for your consideration. I once worked with a guy who some years previously had taken a direct hit by lightning - right in the head. As you might imagine, I asked him what it was like. First, he spent about six months in the hospital. It put him in a coma among other things...

"In short - the Big Bang could not have occurred if the universe is infinite - and the Big Bang has mounds of evidence." this is a common fallacy the particular instance was recently posted in mathforum's "infinity" thread people who actually study the big bang, the CMB, inflation...

what does it mean ?

Maybe I'm a little slow, but the true meaning of pi just occurred to me. tan(pi/4) = 1 arctan(x) = [sum]n=0[oo] (-1)n * [ x2n+1 / (2n + 1) ] pi = 4 * arctan(1) = 4 * [sum]n=0[oo] (-1)n * [ 1 / (2n + 1) ] = 4 * ( 1 - 1/3 + 1/5 - 1/7 + 1/9 - 1/11 + ... ) = 4 * ( 2/3 + 2/35 + 2/99 + ...