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Homework Statement
A woman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. The book has a mass of m = 0.75kg and the coefficient of static friction between her hand and the book is μs = 0.59. What is the minimum force she must apply with each of her hands Fmin in Newtons, to keep the book from falling?
Homework Equations
Weight of Book = mg
Friction Force = μsmg
The Attempt at a Solution
The weight of the book came out to be around 7.35 Newtons and the static friction force came out to be 4.34. I then divided that by 2 to get what I thought was the answer. I figured that the force that is pushing the object (7.35 Newtons) minus the force that was holding it back, friction force(4.34 Newtons) would give me the force needed to hold it without falling.
I feel that I am doing friction force incorrectly as the friction force is usually coming from the bottom of an object and the Normal Force is factored in. In this case, gravity is not playing a part on the friction force (I think) as the surfaces being affected are vertical not horizontal. Even with this assumption, I am not sure how I would go about finding the friction force of an object in this orientation. If the object was lain on an edge on the ground we could easily find the friction force against the floor, but now that it is lifted on 2 sides how would you calculate the one side? Would it perhaps be (.5g)(μs)(kg)?(in an ideal world). All this assuming that my original idea was correct, that I could subtract the weight of the object from the friction force to get the force needed to hold it up, then dividing by 2 to get force each hand needs to apply. Thanks in advance for any and all help.