(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

From Tipler's Physics for Scientists and Engineers(the latest edition)

71.Human blood contains plasma, platelets, and blood cells. To separate the plasma from other components, centrifugation is used. Effective centrifugation requires subjecting blood to an acceleration of 2000g or more. In this situation, assume that blood is contained in test tubes that are 15 cm long and are full of blood. These tubes ride in the centrifuge tilted at an angle of 45.0° above the horizontal. (a) What is the distance of a sample of blood from the rotation axis of a centrifuge rotating at 3500 rpm, if it has an acceleration of 2000g? (b) If the blood at the center of the tubes revolves around the rotation axis at the radius calculated in Part (a), calculate the accelerations experienced by the blood at each end of the test tube. Express all accelerations as multiples of g.

2. Relevant equations

a=v^2/r

v=(2*pi*r)/T

3. The attempt at a solution

First of all the answers are

a)15 cm

b)1300g to 2700g

I honestly don't know how they got part A other than just taking the length of the tube itself, which is 15 cm. Each part of the tube is a different distance from the axis of rotation, so I guess they made a generalization or something.

I do think i know how to get the max an min accelerations though. And also, my webassign is using 16.5 cm as the length of the tube, and I entered that and it counted it wrong, so there must be a different way to find "r"?

any help appreciated.

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# Homework Help: Centripetal acceleration blood plasma problem

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