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Circular motion

  • Thread starter alchemist
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  • #1
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some eggs are placed in a basket. the basket is safely rotated in a vertical plane so that the eggs describe a circle of radius 1 metre. what is the least speed at the top of the circle at which the eggs must move? the ans is 3.2m/s

in this question, i managed to determine the forces present...the weight, centripetal force, i know i am suppose to form 2 equations and solve it, but i have absolutely no idea how to do it...

i could only obtain one eqn: mv*2/r=mg-reaction (at the top of the rotation)
at the bottom it would simply be mv*2/r=reaction-mg

but how do you solve this and obtain the least speed?
are there any other eqn?
 

Answers and Replies

  • #2
HallsofIvy
Science Advisor
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How do you "know" you are supposed to form 2 equations?

Actually your formula is correct. The point is that "least speed" at which the eggs will not fall is the one at which they become "weightless"- at which there is NO reaction.

The equation you need to solve is mv^2/r= mg.
 

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