Statics - Impending motion, moments help

AI Thread Summary
The discussion focuses on determining the force required to tip a cup filled with 6 oz of coffee, with the center of gravity at point G. The user calculated the force needed by summing the moments around point A, arriving at a value of -0.5 lbs, but questioned whether to include a normal force in their calculations. Other participants affirmed the approach and provided encouragement. The conversation also includes a request for feedback on another related problem. The thread highlights the importance of understanding moments and forces in static equilibrium scenarios.
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Homework Statement


The cup shown in the picture is filled with 6 oz of coffee. The center of gravity is located at G. If a vertical force is applied to the rim of the cup a shown in the picture, determine its magnitude so that the cup is on the verge of tipping.
14vpbtd.jpg


Homework Equations



sum of moments = 0
sum of forces = 0
w=mg

The Attempt at a Solution


I summed the moments around point A and came up with the force = - .5 lbs.

not sure if that's right, Do I need to factor in a normal force?

Thanks!
 
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