Surface Integral: Calculating Max Area from Circular Log

In summary, the conversation discusses finding the maximum area of a rectangular timber section that can be obtained from a circular log with a diameter of 0.5m. The conversation suggests using geometry to find a relation between the sides of the rectangle and its diagonal, or using the formula for a circle to differentiate and solve for the maximum area. Reference to a square with diagonal length equal to the diameter of the log is also made.
  • #1
delefemiaoa
6
0

Homework Statement



A log of wood which is approximately circular in cross section has diameter equal to 0.5m. Calculate the maximum area of the rectangular timber section that can be obtained from the log.

Homework Equations





The Attempt at a Solution


No idea of solution
 
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  • #2
You have to at least get started. Draw a circle with a rectangle inscribed in it. Label the sides x and y. Can you find a relation between x and y? Use geometry.
 
  • #3
I have done that before but I can not deduce any relation between x and y.
 
  • #4
Finding that maximum area should be simple if you can assume that the greatest area amoung rectangles is always taken by a square. When you drew the picture, you should have seen a square with diagonal length equal to the diameter of the log. You can use the Pythagorean theorem to determine the relation between the sides of that square and its diagonal length.

But since this is posted under "Calculus" I presume you are intended to show that by differentiating a formula. And, if you are taking Calculus, I suspect you are assumed to know the formula for a circle of radius R with center at (0,0). If you don't know it, you should try to look it up.
 
  • #5
Thanks a lot, I can now understand how to solve it.
 

Related to Surface Integral: Calculating Max Area from Circular Log

What is a surface integral?

A surface integral is a mathematical tool used to calculate the area of a curved surface. It involves breaking the surface into small pieces and summing their areas to get an accurate measurement.

How is a surface integral different from a regular integral?

A regular integral calculates the area under a curve in a two-dimensional plane, while a surface integral calculates the area of a curved surface in a three-dimensional space. It involves integrating over a surface rather than a line.

What is the significance of calculating the maximum area from a circular log?

In mathematics, optimizing a function means finding the maximum or minimum value of that function. In the case of a circular log, calculating the maximum area can help determine the largest possible surface area that can be cut from the log, which can be useful for applications such as woodworking or construction.

What are the steps involved in calculating the maximum area from a circular log using a surface integral?

The first step is to set up the integral, which involves defining the bounds of the surface and the function to be integrated. Then, the integral is evaluated using the appropriate techniques, such as substitution or partial fractions. Finally, the result is interpreted in the context of the problem to determine the maximum area.

What are some real-world applications of surface integrals?

Surface integrals have many practical applications in fields such as physics, engineering, and computer graphics. They are used to calculate electric or magnetic flux, fluid flow, and surface area in 3D modeling. They also play a role in calculating the mass and moment of inertia of an object.

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