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Advanced Math/volume of washer in sq. in.

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Expert: Sherry Wallin - 7/11/2009


Question
Item is 1.895 O.D. x 1.625 I.D. x .437 thk. What is volume?
Answer needs to be in square inches.

Answer
Alan, the answer will NEVER be in square units, you are talking VOLUME which is ALWAYS cubic units. With that said you need to find the area of the washer in square inches and then multiply the area by the thickness. Think of it this way: you have two circles and you want to find the area of the larger circle and subtract off the area of the smaller circle to get the area of the washer.
A(large circle):pi*[1.895/2]^2 ~= .898*pi
A(small circle):pi*[1.625/2]^2 ~= .660*pi
A(large circle) - A(small circle) = .898*pi - .660*pi = ~.238*pi
V(washer) = .238*pi*.437 = ~.104*pi cubic inches ~= .327 cubic inches.

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Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

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