Physics Help: Calculating μ sub s and μ sub k

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To calculate the coefficients of static (μ sub s) and kinetic friction (μ sub k), experimental methods are typically used. In the provided example, a 95 kg clock requires a 650N force to initiate motion, indicating that μ sub s can be calculated as the ratio of the maximum static friction force to the normal force. Once in motion, a 560N force is needed to maintain constant speed, allowing for the calculation of μ sub k as the ratio of the kinetic friction force to the normal force. The discussion highlights that μ sub s should be less than 650N and greater than 0N, as static friction prevents motion until the threshold is reached. Understanding these concepts is crucial for solving physics problems related to friction.
ItsNoah
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Hi all, I just registered for this forum and I am excited to learn a lot! I am taking physics this year and I am enjoying it a lot although it is quite difficult for me.
Quick question:
how do I calculate μ sub s and μ sub k(formulas would be excellent)?
Thanks!
 
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If you're talking about the coefficients of friction for objects, they are typically determined by experiment.
 
Pengwuino said:
If you're talking about the coefficients of friction for objects, they are typically determined by experiment.

For example: A 95 kg clock initially a trest on a horizontal floor requires a 650N horizontal force to set it in motion. After the clock is in motion, a horitzontal force of 560N keeps it moving with a constant speed. Find μ sub k and μ sub s between the clock and the floor.

I said the μ sub s was < 650N and > 0 N would that be correct since static friction means it's not moving and if it's between 0 and 650 it will be staying at rest?
 

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