Head Definition and 391 Threads

Homework Statement A person is standing outdoors in the shade where the temperature is 28 degrees C. What is the radiant energy absorbed per second by his head when it is covered with hair? The surface area of the hair (assumed to be flat), is 160 cm^2 and its emissivity is 0.85. Homework...

Homework Statement Two cars, one a compact with mass 1200 kg and the other a large with mass 3000 kg, collide head on at 60 mi/hr. a. Which car has a greater magnitude or momentum change? Which car has a greater change in velocity? b. Which car's occupant's would you expect to sustain...

if you stood on a mountain would you be able to look straight ahead with a powerful telescope and see the back of your head? or would you just look out into space?

Man I hate forgetting. What I've done so far is log my study times to optimize my spacing. The logs are put on the first page of my binders. Let's say on Day 1. You learned a new concept, the class took 1 hour. You go home and do the 3 hours of practice homework. How long will it take on...

Homework Statement In Figure 6-62 a fastidious worker pushes directly along the handle of a mop with a force . The handle is at an angle θ = 40° with the vertical, and μs = 0.61 and μk = 0.48 are the coefficients of static and kinetic friction between the head of the mop and the floor. Ignore...

http://www.google.com/hostednews/ap/media/ALeqM5he5maBJhjnx6v5XMKAQT9UcI_rjg http://www.google.com/hostednews/ap/article/ALeqM5h5d2mCkhRUjwl0pEAXfoSKpIc-TgD97A3AJO0

End effector with "fish head" kinematics Hallo, I'm student and I have learned and read about end effector of robots. Could you recommend me some articles, www pages, pictures or videos about end effector with "fish head" kinematics? Do you know companies, which sell or development end...

"shower head" for feeding water onto a solar thermal panel Homework Statement The question is homework to me, but I haven't actually seen formal physics classwork since college, 41 years ago. Please advise if this question is misplaced. I'm building a "shower head" to trickle or spray...

Trying to get my head around some basic exterior calculus concepts So #1 - 1-form or covector the grad is a covector / 1-form defined as something that combined with a vector takes it to a scalar, for example divergence is a scalar which is the dot-product of a function with its grad (e.g...

Hi there! I was trying to solve an equation but got very perplexed by the fact that a certain number x=0 is both a solution and no solution: Here´s the equation: (x-a)[(x-a)^2+y^2+z^2]^{-3/2}+(x+a)[(x+a)^2+y^2+z^2]^{-3/2}=0 assume y=z=0: Now, the equation becomes...

Sorry, but my math is a bit rusty but -- Recently while using a wheel chair I fell from a lift banging my head on a marble floor. the lift was 6 feet off the ground, plus adding 4 feet while in a sitting position, the total fall was between 9 and 10 feet. Could someone help me calculate the...

how to calculate head loss due to sudden enlargement in case of compressible fluid? hiiiiii guys, am graduate student, i want to know @ head loss in case of compressible fluid due to sudden enlargement...pls help me ...as soon as possible...

[FONT="Times New Roman"][SIZE="4"]Hi all, I want to know the details of the pumps such as [SIZE="4"][FONT="Times New Roman"]Which of the pump has the highest head? Which one has the Highest Discharge? The one highly recommended for lubrication oils? [FONT="Times New...

So I know I am getting in over my head here, which is why I haven't started anything. I have never done any advanced electronics work, but I know what resistors, capacitors, ICs, and the like are. I can't design a circuit aside from a switch and an LED, but I can build them. Ok, enough of that...

Im in 2nd year of math now...so I know algebra but I was reading this from this website: "Substitution Every time we replace a part of an expression with a value or another expression, we are using the technique of Substitution. And, every time a substitution is performed, parentheses...

As far as i know, a dimension is basically spatial parameters in which "stuff" can move. I think that what bugs me the most about physics is that we know the what but not always the why... obviously this is not anyone's fault especially because finding out why things are the way they are is much...

So in a tape recorder, the quantity of magnetic moment imparted to a unit area of magnetic tape is not a linear function of the applied magnetic flux; the transfer function looks kind of like a cumulative distribution function, if that makes sense. So if one just ran an audio signal directly...

"Head First Physics" - view book via Safari trial or Google O'Reilly Books have recently released Head First Physics, which is an algebra-based introduction to the mechanics and experimental topics in the AP Physics B and A Level Physics courses. The book works from the ground up, using...

http://news.yahoo.com/nphotos/Democratic-presidential-candidate-Sen-Barack-Obama-Jean-Charles-de-Castelbajac/photo//081003/481/b9bd8c072fdd4d8da8a10d013c9fe226/;_ylt=Aq8nHiXTS2gphRnpQIRr24UDW7oF Needless to explain the French prefer Obama.

will it be correct if i define head on collision something like this: When, in a particular reference frame, the direction of velocities of two bodies lies along the common normal, the collision can be called head on even if their Center of masses doesn't lie along their common normal.

A kind of the trigonometry question... Let θ be an angle in standard position such that cotθ=-4/3 and sinθ<0. Determine the exact value of sec θ Determine the number of solutions for (asinx-b)(acosx-a)(bsinx+a)=0 where 0≦x＜2\pi, if 0＜a＜b. A fair coin is tossed 60 times...

I have just swapped some parts for an A7 twin carb head, these heads are like gold dust as there are so few remaining and it is in perfect nick :!) So have you ever found gold dust?

1. failed erudition 2. eggcorns 3. malapropisms

The inventor of a water wheel claims that his design is better than a conventional overshot or breast wheel at extracting energy from water flows at low heads. He states that the design shown can generate up to 260 W of power from a head of 0.8 m. average household energy use over a 24-hour...

Homework Statement The Taylor series for f(x) = ln(sec(x)) at a = 0 is sum_(n=0to infinity) c(sub n) (x)^n. Find the first few coefficients. The Attempt at a Solution I've been trying to figure out where to start by looking it up...I've seen instructions that each coefficient is...

Does anyone know what the pressure is inside the cylinder of an internal cumbustion gasoline engine at the expansion phase? I've been doing some research and I've seen answers ranging from 200psi to 600psi. seems like a significant range, does anyone know where i can get somewhat more accurate...

http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9086098

http://www.time.com/time/magazine/article/0,9171,891156,00.html" So, perhaps one can transplant a terminally ill patient's head into someone's neck for a while (just like in case of Demikhov's dog experiments). Then one waits until a suitable donor becomes available and transplants the head...

We have a new hygiene head and she has just ordered her staff to wash bearings. omg, i have told her bearings need grease and i thought she understood but no, i re greased them and hygiene washed them again, well i am Holiday from tonight so i will leave a note in the book (expect machine to...

I was wondering, I have heard that watching a blinking light can give you a head ack and a seizure. Why does that happen because our computer screens and tvs, are just blinking lights. They blink at about 60-80 times a second.

Help with Allen Head Cap bolts... Hi, Received today a new headphone amp. It is aluminium construction and uses 4 allen cap bolts at each end to hold the case together. It is all good (was cheap), but the bolts used are clearly low quality and don't look right. I would like to replace them...

My fluid dynamics is rather weak and i was wondering if someone could please tell me how to calculate dynamic head of the flow in the a tube and how to calculate pressure drop of a hole in a tube? Some formulas would be handy thanks engineering

Homework Statement The pilot of an aircraft wishes to fly due west in a 50.0 km/h wind blowing toward the south. The speed of the aircraft in the absence of a wind is 205 km/h. a.In what direction should the aircraft head? b. What should its speed be relative to the ground? Homework...

so i have this question about a ladder and the area under it and when it all comes down to it I get the integral, ∫ u2 ( 1 – u2 ) 3/2 du, from u = 0 to u = 1. I am not sure whether to use trig substitution. I keep ending up in the same boat when I do. . . And the same thing when I do...

Homework Statement Please refer to the image attached for problem statement and diagram. There's an inductor somewhere, but I have no idea where and I don't know how to accommodate for it. I can also see that there's another energy storage device, the spring on the right. I have no idea...

Homework Statement In this device, an arm 8.84g long rotates about one end in a horizontal plane, and the astronaut is strapped in at the other end. Suppose that he is aligned along the arm with his head at the outermost end. The maximum sustained acceleration to which humans are subjected in...

Draw the vectors head to tail so they make a triangle

Homework Statement You are on the roof of a physics building, which is 46.0 m above the ground. Your physics professor, who is 1.80 m tall, is walking alongside the building at a constant rate of 1.20 m/s. If you wish to drop an egg on your professor's head, how far from the building...

Constructive criticism please: In 1975, Hillary Putnam published a paper entitled “The Meaning of ‘Meaning’”, in which he proposed an interesting “thought experiment” (see Putnam, H; “The Meaning of 'Meaning'” In Philosophical Papers, Vol. 2: Mind, Langauge and Reality. Cambridge University...

Which country has the potential to have the highest GDP per head of population if its economy was run perfectly? Can one country run a perfect economy if its trading partners do not? Is there a country that can get by on its own with internal markets?

I'm about to begin a bachelor of science with a physics major. I've already found some books on electrodynamics and relativity and such, but I can't find the motivation nor resources to intepret some of the more abstract mathematics, especially to do with linear algebra, tensor analysis and...

It's been a looooooong time since I delved into fluid properties. I'm trying to predict flow based on a known static head. I have a water column which will result in 6 psig of static head. The height of the water column will not change during the flow. I know the downstream piping will...

Hi everybody, The area of a tennis racquet head size is like an egg shape, not oval shape. how to calculate it? Thank you so much for your help ^_^

Just asking the PF members out of interest (and because this stupid Dragonforce song won't go away). Which songs always get stuck in your head?

Homework Statement Heated air at 1 atmosphere and 35 deg. Celsius is to be transported in a 150 meter long circular plastic duct (smooth) at a rate of 0.35 cubic meters/sec. If the head loss in the pipe is not to exceed 20 meters, determine the minimum diameter of the duct. Homework...

Homework Statement A bug lands on top of the frictionless, spherical head of a bald man. It begins to slide down his head. Show that the bug leaves the head when it has dropped a vertical distance 1/3 the radius of the head. Homework Equations Not sure. Maybe: E_f - E_i = 0...

So, I've been very busy shopping around for labs to apply to for my Phd thesis. Last week I went to a conference where I heard a talk on a new discovery that really captured me and made me want to to my thesis work there. I looked the guy up and it turns out, he's from one of the top tier...

Coin toss with rule "+1 if it is a head and -1 otherwise" 25 < my age < 54. Start from the number of my age and toss a fair coin, plus one if it is a head and minus one otherwise, on average, you need to toss 210 times to hit the bound, i.e. 25 or 54. There are two integers satisfying the...

because I keep getting jammed up here, Using u substitution \int \frac{dx}{e^x} I don't see what else to let u equal besides e^x. ...

Hi all, I'm sure a lot of you know about the head loss due to sudden expansion: Hl = (1/2g)*(v1-v2)^2 This equation can be derived from Bernoulli, continuity and momentum balans equations. The underlying assumption in deriving this equation is that the pressure just after the expansion...