Can the coefficient of static friction be calculated from given information?

AI Thread Summary
A 10KG block on a 30-degree inclined plane raises the question of calculating the coefficient of static friction. The force of friction can be determined, and since static friction is defined as the product of the coefficient of static friction and the normal force, it seems possible to calculate the coefficient. However, static friction varies with the applied force, and while the block is stationary, the coefficient represents maximal static friction, not a fixed value. Therefore, the exact coefficient cannot be determined without additional information about the forces acting on the block. The discussion highlights the importance of understanding the distinction between static friction and maximal static friction.
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A 10KG block is resting on a plane inclined at an angle of 30 degrees from the horizontal. Find the force of frction holding the block stationary. is it possibel to calculate the exact coefficient of static friction from the above information? explain.


for this quesiton, I can find the force of friction. BUT, since:

static friction = coefficient of static friction * normal force

from the above equation we can solve for the exact coefficient right? since we know the normal force & the friction force.

now i know static frition will vary depending on the force acting on the object, but since the block is stationary, and the force of gravity acting on it is constant, which mean the coefficient of static will not change.

why can't we find the the coefficient of static friction?

:confused:

edit- ops...i just noticed...i should have posted in the classcial physics group...err...can some mod help me move this topic there?
 
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Because the coefficient is the coefficient of MAXIMAL static friction,not the coefficent of static friction per se.
 
ahhh......thx.
 

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