Calculate Volume of Solid with Hole: Ball of Radius 12 and Hole of Radius 7

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SUMMARY

The problem involves calculating the volume of a solid formed by a sphere of radius 12 with a cylindrical hole of radius 7 drilled through its center. The correct approach to find the volume is to subtract the volume of the cylinder from the volume of the sphere. The volume of the sphere is calculated using the formula \( V = \frac{4}{3} \pi r^3 \) and the volume of the cylinder using \( V = \pi r^2 h \). The exact answer can be derived using integration techniques, specifically by applying the equation of a circle and the indefinite integral formula for volume.

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  • Knowledge of integration techniques in calculus
  • Familiarity with the equation of a circle in Cartesian coordinates
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  • Study the volume formula for spheres and practice calculating volumes of different spheres
  • Learn about the volume of cylinders and how to apply it in various contexts
  • Explore integration techniques, particularly indefinite integrals, for calculating volumes of solids of revolution
  • Investigate the geometric interpretation of equations of circles and their applications in three-dimensional geometry
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Homework Statement



A ball of radius 12 has a round hole of radius 7 drilled through its center. Find the volume of the resulting solid.

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The Attempt at a Solution



I tried to do it as though it is a ball with a radius of 12 missing a ball with a radius of 7 from its center and got an answer around 2900. But it is actually a ball with a radius of 12 with a hole of radius of center, if that makes sense. Like you could see through the ball. I have no idea how to approach this..
 
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Do you need an exact answer? You could approximate it very easily by using the volume of a sphere with 12 as it's radius and subtract the volume of a cylinder with radius 7 and height 12?

edit: The exact answer is obtained (one way) by using the equation for a circle (x*x + y*y = r*r, solve for the necessary variable) and the indefinite integral formula for finding volume (remember to choose the right limits).

First consider the case where the semi-circle is touching the Y axis. What is the radius of the hole generated by the volume created by revolution about the y axis?

picture:

http://img132.imageshack.us/img132/1650/helpbn7.jpg
 
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