Area Definition and 1000 Threads

Homework Statement As in the photos Homework EquationsThe Attempt at a Solution my working is (6.43x10^-3)(310+10) + (11x10^-3)(155) / (6.43x10^-3 +11x10^-3 ) = 215.8 , but the ans is 112 , what's wrong with my working ?

Homework Statement total area = (75x175) +(100x175) +(0.5x50x175) -(π/4 x100x100) = 27964 my centroid for y = (75x175)(87.5) + (100x175)(87.5) +(0.5x150x75)(25) -(π/4 x100x100) (175 - (4(100)/3π) ) / 27964 = 97.13 my centroid for x = (75x175)(37.5) +(100x175) (125) + (0.5x50x175)(225)-(π/4...

Homework Statement The tangent line of a curve y=e^(-x) intercepts the axises at points A and B. What is the maximum area of a triangle AOB considering O as the origin. Homework Equations Ar= xy/2 The Attempt at a Solution Derivative of this function is y'=-e^(-x) I took the formula of the...

i want to calculate area under the curve but i do no not know what function does it satisfies. how should i proceed ?

Homework Statement A stone is thrown into still water, forming ripples which travel from the center of disturbance in the form of circles. If the circumference of the circle which bounds the disturbed area is 10 ft and the circumference is increasing at the rate of 3 ft. per second, how fast is...

Homework Statement Find the area of the region between the graphs of: y=x^3+3x^2+5x and y = x^3+2x^2+7x on the interval [-1,2] The Attempt at a Solution I am not entirely sure what they mean by the REGION between the graphs, is this the region which encloses an area when the two functions...

Homework Statement We have: I=nAve Imagine a copper wire with a constant current through it: I=constant e=constant n (for copper)=constant Hence, we obtain: A is inversely proportional to electron drift velocity. My question is: how does that make sense? Why would the cross sectional area...

It is possible to find area of triangle or parallelogram in euclidean by using matrix determinant composed of unity, x coeffs and y coeffs in row1,2,3 respectively. Is it possible to do that in higher dimensions as well although it may be not as simple as in 2D case. In 3d matrix composed of...

Homework Statement I'm answering a question which describes a situation in which a metal ring is dropped through a magnetic field such that, when it falls, its area is perpendicular to the magnetic field. I need to find its terminal velocity given: Mass : 2.66 x 10-4 kg Magnetic flux density ...

Homework Statement i have a few question here . 1. the y bar for I should be 16.98, am i right ? 2. The y bar for II should be 50+12+24=86 , am i right ? 3. the x bar for V should be 50 , am i right ? Homework EquationsThe Attempt at a Solution

Hi, So for a piece of maths coursework I am thinking of trying to calculate the surface area of an atom or molecule. I do not know whether it would be viable because there isn't a clear boundary for an atom/molecule due to the electron clouds. However I wanted to know if I could do something...

Is there a relatively simple algorithm to compute the area in percentage under the curve as represented by a sigma value? For example; 3 sigma = 99.7 2 sigma = 95 1 sigma = 68.3 Now suppose I wanted to know 2.5 sigma without a table.

Homework Statement why the y bar is 0 ? according to the diagram , y ' has certain value , it's not 0 ! can someone help to explain ? Homework EquationsThe Attempt at a Solution

Two numerical methods for finding the area under a curve are the trapezium rule, where the area is split into trapezia, and the rectangle rule where you split into rectangles. The rectangle rule has two forms, one where you take the height at the midpoint and one where you take the height of the...

Hi, I have an mathematics assignment to do, and I wonder if the topic I have chosen is doable for me. I want to minimize the surface area of a cobbler cocktail shaker, and until now my plan was to get the curve equation for the side of it, and get the area equation from surface of revolution...

1. Problem: ellipse x^2/a^2 + y^2/b^2 = 1 encloses circle x^2 + y^2 = 2x. Find values of a and b that minimize the area of the ellipse.Homework Equations : [/B]A = pi*a*b for an ellipse.The Attempt at a Solution : [/B]I tried a bunch of crazy stuff... I know I need to find where the tangents...

http://edugen.wileyplus.com/edugen/courses/crs7165/art/qb/qu/c29/pict_29_93.gif if I wanted to find the area of the outer circular strip, I know I would just take the area of the composite and subtract out the inner radius. (i.e. pi(a^2)-pi(b^2)). However why can't I use...

Homework Statement In a jet engine, a flow of air at 1000 K, 200 kPa, and 40 m/s enters a nozzle, where the air exits at 500 m/s and 90 kPa. What is the exit temperature, inlet area, and exit area, assuming no heat loss? Homework Equations min = mout = m where m = mass air flow dE/dt cv = Qcv...

How was the equation for area of a ring derived?

I solved the equilibrium equations and found that link BD is in tension while link CE is in compression, but my resulting answers for normal stress were wrong. The solutions show that the cross area to be used for normal stress at links BD and CE should be different. Link BD should incorporate...

[FONT=Georgia]Hoping to clarify something about this... Is it fair to say that you should consider the relationship between pressure and area as a function of whether a fluid is moving or standing still? In other words, when a fluid is moving and you decrease the area, the pressure goes down...

Homework Statement Find the area of the region in the plane where, r2sin(2theta) >2(sq.root3) , r^2 < 4 Homework EquationsThe Attempt at a Solution To try to visualize the problem a little better I converted from r2sin(2theta) to 2xy. However I'm confused after this, since I don't know what...

Homework Statement See pictures. There are 2 parts to the problem but I can probably figure out the second part once I get the first part. [/B] Homework Equations Antinodes (minimum pressure) at Nodes (maximum pressure) at [/B] Equation for a standing wave: The Attempt at a Solution...

If A = x y (if the area of the paralelepid A is equal to edge x multiplied by edge y), so, dA is equal dx y + x dy. See: But this is so much incovenient! The convenient would be dA = dx dy. Let's see now d²A... d²A = d dA = d²x y + dx dy + dx dy + x d²y Now dx dy appears! But, is not a...

Mod note: Edited the following to remove spoiler tags and to put code in code tags Homework Statement Hi, currently I have this assignment: Write a program by going through the 6 problem solving steps that reads in the length and width of a rectangular yard in feet, the length and width of a...

First of all I don't mean a rotating circumference, but rather a translating one which is also rotating. Like this one: https://www.desmos.com/calculator/4vdymlzgpp just play the p button. I understand that the x component of the movement is: and Y= (where v is the radius, s is the angular...

Homework Statement The figure below represents part of the performance data of a car owned by a proud physics student. (The horizontal axis is marked in increments of 2 seconds and the vertical axis is marked in increments of 10 m/s.) (a) Calculate the total distance traveled by computing the...

My maths teacher taught me a shortcut for finding area bounded by curves of the form: $$|as+by+c|+|Ax+By+C|=d$$ Shortcut: Let required area be ##A_0## and new area after "transformation" be ##A## Then, $$A_0\begin{vmatrix} a& b\\ A& B\end{vmatrix}=A=2d^2$$ All I understood was the ##A=2d^2##...

Hey there! While reading my mechanical design book, I had hard time to understand a particular paragraph if anyone could help. Attached to this post are two figures. 2-6 a and b. The first one is pretty simple to understand; the engineering normal stress strain curve...

Suppose you have a given area under a curve, say 250, and want to come up with a function that produces this value. How would you do this? Although I came up with two basic functions as follows:First: Let y (x) = 5 from 0<x<50 , thus length*width = yx = 5*50 = 250. Second: Area of a...

As seen in the drawing attached, there are two circles, the first circle will be a container to hold water and the outer is a second layer of aluminium, in between these will be insulator. What is the best way to work out minimum space lost by using triangles/sectors to fill this area? Having...

Homework Statement What is the area of a triangle on Earth that goes from the North Pole down to the equator, through the prime meridian, across the equator to 30 degrees east longitude, then back up to the equator? The radius of the Earth is about 6378 km. Homework Equations alpha + beta +...

Homework Statement We have a sensor onboard a satellite that is faced towards Earth, from the Sun. The LW absorptivity is 0.8 (a_LW) and SW is 0.2 (a_SW). I need to find a equation for the temperature as a function of time. Given datas is the Area=0.3 m^2 and Specific Heat of 4 J/K Homework...

Homework Statement A closed curve C is described by the following equations in a Cartesian coordinate system: where the parameter t runs monotonically from 0 to 2π, thus defining the direction of C. Calculate the area vector of the planar region enclosed by C, using the formula: 2. The...

Hi all Making this title was harder than I thought. It certainly makes the topic look more advanced than it actually is. I studied differential geometry during my masters but never went much in depth, just enough so I could apply basic concepts to my specific problems at the time. Now I'm...

Let's consider the Magnetic hysteresis loop of a certain material: https://www.nde-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/HysteresisLoop.htm is an example. In many sites and books it is written that its area is proportional to the energy wasted as heat, so A = kE_d. In...

Homework Statement Given a circle with a set diameter, how does one calculate the area of the segment below? Homework Equations The only information available is the diameter (in this particular example it is 14"), You may not use angles. Only the chord length. Thank you for your reply. Miguel

Hi Forum, Just wanted to ask how to compute surface area of a helix x =cos t, y =sin t, z=t by integration Thanks in advance.

When I learned about volumes of solids of revolution, I never really memorized any formulas for specific cases per se. I used two expressions for area, either ##A = \pi (R^2 - r^2)## and ##A = 2\pi r h##. Those expressions worked for rotations about any horizontal/vertical axis (not necessarily...

Hello everyone, I'm using the book Apostol- Calculus Vol. 1 for self-studying to get a better understanding of proof based Calculus. They said this book was good for self studying, but I am already stuck in the first chapter. I'm trying to understand how he got the identity: 12+22+...+n(2)=...

Δ≤ Homework Statement Find final velocity. Knowns: m = 4kg Initial v = 0 m/s F = Asin(xt) F = (2000N)(sin(\frac{1000π}{sec}*t) (0sec ≤ x ≤ .001sec) We need to find the impulse from a Force vs. Time graph. There is a preface to this problem that says if we work out the Force function...

My books and my teachers tell me that the frictional force is independent of the area of contact. I am also aware of the equation F=μN and that area has no part in it. But it's just so confusing and counter-intuitive. Friction is because of the the interlocking of the irregularities of two...

I have a question about a seemingly illogical and strange aspect of multiplication and unit conversion that I have never noticed until now. It concerns the issue of finding the area of a square/rectangle when the length and width are expressed as decimals/fractions. Ordinarily, when you find...

I am designing a mask for a chip which might be used for wirebonding. What is the minimum contact area for wirebonding using a microscope and microprobe? Currently my contact pads are 220 x 220 um. Is that big enough?

A hypodermic syringe contains a medicine with the density of water (figure below). The barrel of the syringe has a cross-sectional area of 2.18 10-5 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force of magnitude 1.78 N is exerted on the plunger, making...

I understand how surface area does not come into the equation governing the resistance an object has to sliding. It leads one to believe that all tires would perform equally in dry conditions. Why do people then say that bald tires give better grip?

I almost understand how the inverse square law is derived from the area of sphere equation, 4πr2, but I'm not quite clear on what happens to the 4π. I found one equation that seemed to say that the intensity is equal to the area of the sphere of the source point times the amount of whatever...

Homework Statement Determine a simplified, factorised expression, in terms of the radius (r), for the surface area of a cone where diameter (D) = perpendicular height (h) Homework Equations A = πr (r + √(h^2 + r^2)) The Attempt at a Solution h=D=2r A = πr (r + √(2r^2 + r^2)) A/π = r (r +...

Greetings all, Just thought I'd hear you out on a decision I'm trying to make before applying to graduate school this fall, however going to keep it vague so it doesn't come around to bite me in the butt. I did an REU in physics sub-field A at a school which is #1 in the nation for sub-field...

How can we find that using calculus