Salt Shaker on a Lazy Susan, magnitude of force

AI Thread Summary
Joey's experiment with the lazy Susan involves spinning a salt shaker at the edge to keep it from slipping off, achieving a speed of 0.6908 m/s with a radius of 0.22 m. To determine the magnitude of the horizontal contact force on the shaker, one must calculate the centripetal acceleration, which is essential for an object moving in a circular path. The centripetal acceleration can be expressed as a = v²/r, where v is the speed and r is the radius. With the mass of the shaker measured at 87 grams, the next step involves applying Newton's second law to find the force. Understanding these principles will help solve the problem effectively.
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Mischievous Joey likes to play with his family's lazy susan (this drives Mom crazy because it is an antique). He puts the salt shaker near the edge and tries to spin the tray at a speed so that the shaker just barely goes around without slipping off. Joey finds that the shaker just barely stays on when the turntable is making one complete turn every two seconds. Joey's older sister measures the mass of the shaker to be 87 grams. She also measures the radius of the turntable to be 0.22 m, and she is able to calculate that the speed of the shaker as it successfully goes around in a circle is 0.6908 m/s.

What is the magnitude of the horizontal part of the contact force on the shaker by the turntable?i am so lost, can someone please help me to get this problem started?? i thought i needed to find the acceleration of the salt shaker and used 0 as my starting velocity, but when i went to find the force i didnt come up with the right answer.
 
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A body moving at uniform speed in a circle must have a centripetal acc.
Do you know the expression for this acc?
 
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