Centrifuge Problem (Circular Motion)

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SUMMARY

The discussion centers on calculating the angular velocity and centripetal acceleration of a centrifuge operating at 12,000 RPM with a radius of 150 mm. The conversion of RPM to radians per second yields 1256.64 rad/sec. The centripetal acceleration is calculated using the formula a = rω², resulting in an acceleration of 236,871.61 m/s². This value, while seemingly high, is within the operational range for laboratory-grade centrifuges, which typically operate at high speeds for effective separation processes.

PREREQUISITES
  • Understanding of angular velocity and its conversion from RPM to radians per second
  • Familiarity with centripetal acceleration and its calculation
  • Knowledge of the formula a = rω²
  • Basic concepts of centrifuge operation and its applications in laboratory settings
NEXT STEPS
  • Research the specifications and operational limits of laboratory-grade centrifuges
  • Learn about the effects of varying RPM on separation efficiency in centrifuges
  • Explore the relationship between radius and acceleration in circular motion
  • Investigate safety considerations and best practices for operating high-speed centrifuges
USEFUL FOR

Students in physics or engineering, laboratory technicians, and anyone involved in the operation or design of centrifuges will benefit from this discussion.

GoodOldLimbo
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Homework Statement



A Centrifuge rotates at 12000rpm. What is this in radians per second?

If the radius of this centrifuge is 150mm, what is the centripetal acceleration?

Homework Equations



v2 / r

v = rω

a = rω2


The Attempt at a Solution



First I converted the 12000rpm to 1256.64 rad/sec.

12000 / 60 = 200 Rev. per minute.

200 x 2∏ = 1256. 64 rad/sec

Onto the centripetal acceleration, I was given a = rω2

a = 0.15 x 1256.642

a= 236871.61 m/s2

I'm just a little thrown off by how incredibly large the number is and I don't really have any idea of how a centrifuge usually moves. Any help?

Would be much appreciated.
 
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GoodOldLimbo said:

Homework Statement



A Centrifuge rotates at 12000rpm. What is this in radians per second?

If the radius of this centrifuge is 150mm, what is the centripetal acceleration?

Homework Equations



v2 / r

v = rω

a = rω2


The Attempt at a Solution



First I converted the 12000rpm to 1256.64 rad/sec.

12000 / 60 = 200 Rev. per [STRIKE]minute [/STRIKE]second

200 x 2∏ = 1256. 64 rad/sec

Onto the centripetal acceleration, I was given a = rω2

a = 0.15 x 1256.642

a= 236871.61 m/s2

I'm just a little thrown off by how incredibly large the number is and I don't really have any idea of how a centrifuge usually moves. Any help?

Would be much appreciated.

Welcome to the PF.

I only see one problem in your work, and it's just a simple typo that doesn't change the numbers. See where I fixed it in the quoted text above.

And yes, the acceleration does seem high, but after all that's what centrifuges are for. I used Google to look up some typical specs on labratory-grade centrifuges to see if the acceleration number you calculated is reasonable. The 12,000 rpm given number is pretty fast for the centrifuges that I looked up, but the size is in the typical range.

Convert your acceleration into the number of g's (g = 9.8m/s^2), and compare your answer to what you find on Google. Post what you find so we can see what you are getting...
 
That acceleration value is fine for a centrifuge. And it is still far away from their limits.
 

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