Expert: Sherry Wallin - 11/24/2008

Question
Question: What are the real life applications of the disk/washer integration system to find volume in calculus?

Details: You know how you can find the area between 2 functions by taking the integral, and then you have to use the disk/washer system and flip it around the axis to find the volume?

Well, I was wondering...what are some real-life applications of that? What are its uses?

Answer
Here is one example and there are many more: A CAT scan produces equally spaced cross-sectional views of a human organ that provide information about the organ that are otherwise obtained only by surgery. For example: suppose you wanted to know the volume of a liver and you took cross sections views spaced 1.5 cm apart and the liver is 15 cm long and the cross sectional areas in square cm were
0,18,58,79,94,106,117,128,63,39 and 0. You can use the midpoint Rule to estimate the volume of the liver.

I hope this enlightened you.

Math Prof