Static Friction: Max Force Magnitude Applied?

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The discussion focuses on the properties of static friction, specifically the maximum static friction force (Fs, max) in relation to the normal force. It establishes that Fs, max is not perpendicular to the surfaces in contact, making statement I false. Statement II is confirmed as true, since Fs, max indeed represents the maximum static friction force. The confusion arises with statement III, which suggests that the magnitude of Fs, max equals the applied force that initiates movement; it clarifies that the applied force must exceed Fs, max to cause motion. The thread emphasizes understanding the relationship between static friction and applied forces for accurate problem-solving.
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Homework Statement



Which of the following statements are true about Fs, max in the equation mu=Fs, max/Fnormal?

I. Fs, max is exerted perpendicular to the surfaces in contact.
II. Fs, max represents the maximum value of the force of static friction.
III. On a level surface, the magnitude of the Fs, max equals the magnitude of the applied force that starts the object moving.

Homework Equations



mu=Fs, max/Fnormal?

The Attempt at a Solution



Well, I know that Friction is parallel to the surface and opposite to the direction of the force on the object, so I is out of the picture, and II seems a bit obvious, so that's one true answer. I'm not understanding the third one, though. Help? I just need an explanation to III to know if it is true or false.
 
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The maximum static friction will be at the instant just before the object starts to move. For example, if
F_{S, max}=12.000000000, then I would assume F=12.000000001 would be suffice to induce movement, which is essentially 12.
 

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