A bottle of soy sauce sits near the edge of a circular turntable in the middle of a big family table in a restaurant. As a child spins the turntable with constant angular velocity, which one of the following forces provides the “centripetal force” that keeps the bottle moving in a circle, intead of flying off?
A: Weight
B: normal force
C: tension
D: friction
E: centrifugal force

I know that
centripetal force = (m) * (a) = m * w^2 *r = (mv^2) / r

So the answer must be friction. Am I correct?

Part II: In order to further ensure that the bottle does not fly off, which of the following things could you do?
A: move the bottle closer to the center
B: spin the turntable faster
C: increase the period of rotation
D: make the turntable stickier
E: empty out some of the soy sauce

My answer is either C or D. I know mass is negligent, so that eliminates D. I know that I want a choice that will increase the friction force I chose above. But I’m lose. Help please?

Tags: Centrifugal Force, Centripetal Force, Constant Angular Velocity, Fly, Friction Force, Mv, Open Question, Soy Sauce, Tension, Turntable

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