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Sun 22 Jul, 2007 06:03 am
Is it possible to measure gravitational acceleration 'g' near the earth's surface using a centrifuge? Someone told me that if you put a small object like a pebble in a centrifuge, start the centrifuge off at a high speed, and slowly lower the angular speed. At the speed the pebble falls out, the gravitational acceleration will equal omega squared times r (radius); is this valid? (omega is angular speed, the derivate of the angle with respect to time, or 2pi radians/period if angular speed is constant)
I do not think so, because the force here is the frictional force between pebble and centrifuge, and not the gravitational force.
If not, is there a way to measure 'g' using a centrifuge?
Thank you.
If you swing anything in a vertical, circular pattern, anything inside of it will experience two forces at the top of the arc. If the measurable, centrifugal force is less than the force of gravity, the object will fall.
If you swing an object at a constant angular velocity in the horizontal the object will see two perpendicular acceleration forces, one horizontal and the other vertical due to gravity. The object will then travel along a conical path. if you know the angular velocity, the radius of the path, and path angle with the vertical (or the horizontal) you can use trig to calculate g.
rap
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