Area is the quantity that expresses the extent of a two-dimensional region, shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat. It is the two-dimensional analog of the length of a curve (a one-dimensional concept) or the volume of a solid (a three-dimensional concept).
The area of a shape can be measured by comparing the shape to squares of a fixed size. In the International System of Units (SI), the standard unit of area is the square metre (written as m2), which is the area of a square whose sides are one metre long. A shape with an area of three square metres would have the same area as three such squares. In mathematics, the unit square is defined to have area one, and the area of any other shape or surface is a dimensionless real number.
There are several well-known formulas for the areas of simple shapes such as triangles, rectangles, and circles. Using these formulas, the area of any polygon can be found by dividing the polygon into triangles. For shapes with curved boundary, calculus is usually required to compute the area. Indeed, the problem of determining the area of plane figures was a major motivation for the historical development of calculus.For a solid shape such as a sphere, cone, or cylinder, the area of its boundary surface is called the surface area. Formulas for the surface areas of simple shapes were computed by the ancient Greeks, but computing the surface area of a more complicated shape usually requires multivariable calculus.
Area plays an important role in modern mathematics. In addition to its obvious importance in geometry and calculus, area is related to the definition of determinants in linear algebra, and is a basic property of surfaces in differential geometry. In analysis, the area of a subset of the plane is defined using Lebesgue measure, though not every subset is measurable. In general, area in higher mathematics is seen as a special case of volume for two-dimensional regions.Area can be defined through the use of axioms, defining it as a function of a collection of certain plane figures to the set of real numbers. It can be proved that such a function exists.
I know this sounds like a weird question, but I'm interested.
So I've always loved math, especially pure mathematics. I spend a lot of time reading about theorems, mathematical proofs, and I try to come up with my own proofs. Recently I had the idea that maybe I can spend my time reading some...
I'm have already learn some of Differential,Integral,Multivariable Calculus(with Vector Calculus to), Ordinary Differential Equations, and something in PDEs(i know solve some by the Method of Separation of Variables:woot:), so what should i need to learn in math for areas like Eletromagnetism...
Hello all,
I was hoping some of you who have taken or are currently taking courses in an area unrelated to your major would share something about the experience:
What are the two subjects, and why did you choose to pursue formal education in the second area of study? Did you take only a few...
Given any tetraedron, I want to calculate the volume V in function of the areas of the surfaces of the solid. I found this pdf that explain this:
http://daylateanddollarshort.com/mathdocs/Heron-like-Results-for-Tetrahedral-Volume.pdf
But, o pdf says that beyond of the 4 faces (X, Y, Z, W) is...
Hi!
I'm doing a worksheet on Body Size, Heat Loss and SA/Vol Ratio.
The question I'm confused by is:
"The smallest organisms such as bacteria, protozoa and unicellular algae live in water or a saturated atmosphere. They are only found in dry situations as cysts or spores. Why?"
The wording...
Hi, I'm in first year of my physics undergrad degree in NUIGalway and currently (could change as the four years pass) have an interest in doing a masters in Weapons Engineering after the degree is completed.
In my course we get the choice of specializing in one of four areas: theoretical...
Find the area of the regions shown in the figures.
These are the graphs used :
y = x^2
x = 2 Sin ^2 (y)
I know that I need to set the two equations equal to each other in order to find the points of intersection, but I run into some trouble when trying to simplify it for y.
This is what...
Which research areas for a PhD in Physics may lead to good positions in the Industry's R&D? Please, excuse my English and thank you for any suggestion.
I'm currently a second-year electrical engineering major (in the US). Next semester I'll begin to take almost exclusively classes involving different branches of electrical engineering. I've taken two digital design courses, a course on microprocessors, and I'm currently on my second "circuits...
I'm a graduate mathematics student and I did my undergrad in applied math. I also took the normal 10 hrs of physics foundations and then a semester of modern physics (basic quantum intro, special relativity, orbit states etc.). I was thinking about pursuing study in areas that would be...
Hello, I'm not sure whether this thread should be in a guidance section or here, but I think its more closely related to this area.
As the title of the thread says, what are some current areas of research in Optics, if any?
Thanks for any and all replies
Hello,
I am a physics student and have catagorised most of physics, e.g classical mechanics, relativistic mechanics, quantum mechanics and quantum field theory, and have also identified all the mathematics involved in each of these catagories.
For example classical mechanics involves Calculus...
I'm having trouble evaluating this surface integral. This would be very simple to solve if the parameter domain of the variables u and u was a square region. However, that isn't the case here. I've tried using a change of variables and saying that u = r cos x, and v = r sin x. Where 0 < x < 2pi...
Hello. I'm not a mechanical or aerospace ingineer, but it's interesting for me.
What are the main areas of physics and mathematics for aerospace engineer? It seems to me, that main areas of maths are calculus and differential equations, maybe some linear algebra. And I think, that main areas of...
Hello!
My friend and i are interested in doing a project.My area of interest in Fluid mechanics and my friend's is mechanical design can you guys help us out by providing some topics of research which encircles both these areas.
Hello people,
I just joined the physics forum and it's great to see that they're other physics enthusiasts on the internet!
The reason why modern physics is appreciable for me is that it creates new areas in mathematics like this for example brought up from Michio Kaku... "String theory...
When we generate solid by rotating a curve around an axis, we use "slabs" of cylinders to approximate the volume of this solid of revolution. When we want the find the surface area, we instead use "slabs" of conical frustums (ie. the slope of the differential length of curve is taken into...
Hi all
Hoping someone can figure out a problem. In the attached figure, A is the area of openings in a disc. Assume the segments 82, 84, 86, 88 are along a radius and are equal. Is it possible to prove that A4/A3 > A3/A2 > A2/A1?
In thanks I'll share this, hope it's not old news. Some...
I'm currently in the middle of a Physics PhD program but I now want to drop out with a Masters. I'm considering a career as an materials engineer or EE, but I definitely want to focus more on using software than 'hands-on' work.
I heard that power systems, signal processing, communications...
In hilly areas temp is low than plain areas.So the temperature of source as well as sink must be low.But ratio remains same.So efficiency is same as in plain areas? Is my logic correct? Or anything else? Can it be more?
Homework Statement
Let a > 0 be a fixed real number. Define A to be the area bounded between y=x2,y=2x2, and y=a2. Define B to be the area between y = x2, y = f(x), and x = a where f(x) is an unknown function.
a) Show that if f(0) = 0, f(x) ≤ x2, and A = B then
int 0-->a2 [y1/2-(y/2)1/2] dy =...
Hello all,
I've been trying to work out this problem I came across yesterday when a professor mentioned it in a math education course. It states, "Take a circle and put two dots on the circle then connect them with a cord. How many sections of area does the cord split the circle into?" Of...
Homework Statement
Sketch the region in the first quadrant enclosed by the given curves. Decide whether to integrate with respect to x or y. Then find the area of the region.
y=4cosx, y=6sin2x, x=0.
Homework Equations
The Attempt at a Solution
I got the intersections, which...
Hey! I am going to choose my specialization soon in my engineering physics degree, but I am very uncertain on what I want to do. Only thing I know is that I want to work on something cutting edge.
So what areas of science and tech do you find exciting, and why? Do you know anything about...
Homework Statement
(I have attached the problem to this post as a file)
Homework Equations
In class we learned other fomulas for the area of a triangle using the SAS case, ASA and SSS (Heron's).
The Attempt at a Solution
I am honestly so confused with this one. I have a bunch of random...
In Heath's commentary on Euclid's Elements he stresses the importance of the application of areas (Book I Proposition 44) with, "The marvellous ingenuity of the solution is indeed worth of the 'godlike men of old'...".
The proposition, "To a given straight line to apply, in a given...
Hello all,
I am considering applying for PhD programs in Physics/EE (specifically - Optics/Photonics). Considering pervasive posts about the dismal job market, I understand Optics/Photonics is more applied, and hence more sought-after in industry. However, what areas within Optics/Photonics...
1. The problem in attachments
Homework Equations
3. RNA destroyed means no proteins (enzymes) formed, however if some areas showed no color, does that mean other areas did? I'm pretty sure the answer is D but making sure
Hi,
I just finished my bachelor's degree in chemistry, in which I have made sure to get some extra mathematics and statistics (introduction to calculus, linear algebra, and linear differential equations; experimental design, ANOVA, advanced regression). I feel pretty covered here and ready for...
I will do my best to describe the problem I am working on. The problem is not from a textbook or anything but something I am working on independently to strengthen my first year calculus knowledge.
What I did is I took sin(x) and -sin(x) and graphed them together. Sin(x) and -sin(x)...
the following diagram shows a circle with center O and a radius
4cm
The points A, B, and C Lie on the circle.
The point D is outside the circle, on (OC)
Angle ADC=0.3 radians and angle AOC=0.8 radians
(a) find AD
I used law of sines
\frac{4}{\sin{0.3}}=\frac{x}{\sin{0.8}}
x \approx...
Okay, so I've got a question on graphs and areas under curves.
For example, a force-distance graph, with force on the y-axis and distance on the x-axis, where you find work done from that graph.
I understand that a constant force will produce a horizontal line on the graph, like so:
Force...
Hi to everybody.
I´m reading a book about statics and I cannot understand this chapter. I have been calculating moments of forces in hundreds of problems, when I found a force acting on a body I needed to fix a coordinate system, then calculating the moment arms of that force around a point...
Hey guys I was wondering if a symmetric C-D nozzle has the same area at the inlet and exit, can the mach numbers at both points be the same?
This situation would involve a normal shock which would be near the exit as well. I would assume the Mach number at the throat would be 1.
With that...
I have used the search to find topics on this but to no avail. If there are topics asking this question then please advise me.
I am due to start a degree in computer science in September, here in the UK. It is a life long passion and a degree course I could have never of dreamed of studying...
What areas of math do you need to know in order to understand calculus? Let's assume all I have is up to a 6th grade education. Can you tell me what and how I might learn these things.
Hi, I am trying to design an electrostatic generator that works well in high humidity. At the moment I'm looking at a van de graaf generator and covering the metal sphere with an insulator and only leaving a little bit exposed.
Is this safe? And will it increase the maximum charge?
My...
Hey guys,
I am wondering what is the best type of mini hydro power plant to produce between 1 and 5Kw of energy.
From what I understand most micro generator needs high head, and they take advantage of the relief (since power=head*flow*g)
I am looking at an area where the head is very...
The Question
Let f(x) = |x|. use areas to evaluate ∫(-1,x)f(t)dt for all x. use this to show that d/dx∫(0,x)f(t)dt = f(x)
not sure hot to evaluate the integral using area when i don't know what f(t) is...
Homework Statement
http://www.aapt.org/physicsteam/2010/upload/2010_FmaSolutions.pdf
See question 23
A' = 1/2A
Homework Equations
Av = A'v'
The Attempt at a Solution
I thought this was just a simple Av = A'v' problem
which would lead to v' = 2v. But there is apparently more to it, as the...
Good day,
while reading up on an elementary math study book, i have encountered that a proof is build upon the following (see attachment for the figure).
Are the Areas CDE and BED really the same? I tried to calculate this from abstraction, not sure where I could have made a mistake..
g1 is the...
I'm doing double honours in Neuroscience, likely biochemistry as well. I have to find a thesis adviser for next year...I know everyone says "follow your heart" or something to that effect, but that's not what I'm looking for, not to impugn anyone will kind intent.
Here's my interested in Med...
Homework Statement
from [-2,2] rad(4-x^2)
Homework Equations
The Attempt at a Solution
I know its a circle and i get the equation to be y^2+x^2=4
and I believe it has to be divided into a circle and rectangle
so the area of the rectangle i got to be 2
the circle i got to be...
I am learning this right now, and I am having troubles with something.
For regular partition, the formula in my textbook is this.
x_k=a+k\Delta x, \text for k=0,1,2,...,n.
My question is this, how does one find "k"? It is very important clearly!;)
I am interested in how to protect electronics circuit in hazard areas
Are there special ways of soldering /circuit arranging for highly vibrational places ?
moist/water protection ?
Impact ?
Hi temperature ?
Special box materials for examples above?
etc...
tnx ;D
Müller's law seems to differ from the modern statement of the law in one key way. Müller attributed the quality of an experience to some specific quality of the energy in the nerves. For example, the visual experience from light shining into the eye, or from a poke in the eye, arises from some...
Hello,
Here are the known's of a chassis:
Inlet open area = 17 inches^2
Outlet open area = 30 inches^2
Internal Fans = 270 cfm (3 fans @ 90 cfm each)
What is the CFM through the system and what's the equations used to figure this out?
I assume that if we had a very small inlet or...