Need help with centripetal acceleration problem.

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SUMMARY

The forum discussion centers on calculating centripetal acceleration using an analytic ultracentrifuge. The biophysicist needs to determine the centripetal acceleration at a radius of 0.084m while spinning at 6.0 x 104 rpm. The correct formula for centripetal acceleration is applied, yielding a result of 3.32 x 107 m/s2. The final answer must be expressed in terms of g (9.8 m/s2), leading to the conclusion that the centripetal acceleration is approximately 3.39 x 106 g.

PREREQUISITES
  • Understanding of centripetal acceleration formula: ac = 4π2rf2
  • Knowledge of unit conversions, specifically between meters and centimeters
  • Familiarity with angular velocity and its conversion from rpm to seconds
  • Basic grasp of gravitational acceleration (g = 9.8 m/s2)
NEXT STEPS
  • Review the derivation of the centripetal acceleration formula
  • Learn about angular velocity conversion from rpm to rad/s
  • Study the implications of expressing acceleration in terms of g
  • Explore applications of centripetal acceleration in biophysics and centrifugation techniques
USEFUL FOR

Biophysicists, physics students, and anyone involved in laboratory techniques requiring the calculation of centripetal acceleration in centrifugation processes.

Imperil
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PROBLEM
A biophysicist wants to separate sub-cellular particles with an analytic ultracentrifuge. The biophysicist must determine the magnitude of the centripetal acceleration provided by the centrifuge at various speeds and radii.

Calculate the magnitude of the centripetal acceleration at 8.4cm from the centre of the centrifuge when it is spinning at 6.0 x 10^4rpm. Express your answer in terms of g (acceleration due to Earth's gravity).

MY ANSWER
r = 0.84m
f = 6.0 x 10^4rpm = 1000s

ac = 4pi^2rf^2
= 4pi^2(0.84m)(1000s)^2
= 3.32 x 10^7 m/s^2

So now that I have the centripetal acceleration I'm unsure of how to express my answer in terms of g as per the second part of the question. What I did was the following:

ac / g
3.32 x 10^7 m/s^2 / 9.8 m/s^2 = 3.39 x 10^6 m/s^2

but I am second guessing this because I really have no idea why I dividedt he acceleration by the acceleration of Earth's gravity. Could somebody shed some light on this and if I am wrong?
 
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ac / g
3.32 x 10^7 m/s^2 / 9.8 m/s^2 = 3.39 x 10^6 m/s^2

You have to wright the answer as
(ac / g)*g
3.32 x 10^7 m/s^2 / 9.8 m/s^2 = (3.39 x 10^6 )g. That is whar required.
 
Imperil said:
Express your answer in terms of g (acceleration due to Earth's gravity).

ac = 4pi^2rf^2
= 4pi^2(0.84m)(1000s)^2
= 3.32 x 10^7 m/s^2

So now that I have the centripetal acceleration I'm unsure of how to express my answer in terms of g as per the second part of the question. What I did was the following:

ac / g
3.32 x 10^7 m/s^2 / 9.8 m/s^2 = 3.39 x 10^6 m/s^2

but I am second guessing this because I really have no idea why I dividedt he acceleration by the acceleration of Earth's gravity. Could somebody shed some light on this and if I am wrong?

Some light has already been shed, but I'm just asking you this simple question: if ac was equal to, say, 4.1*9.8 m/s^2, how much would it be in terms of g?
 
Bro...The QUestion Stated that r=8.4cm, so r=0.084m not r=0.84m...Correct that and so u r answer would be one decimal off...right answer would be ac= 3.32*10^6...in terms of g = 3.39*10^5 no unit.
 

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