What is the Coefficient of Friction for a Lab Using Spring Scales?

AI Thread Summary
The discussion focuses on calculating the coefficient of kinetic friction using spring scales, with a mass of 0.411 kg and a normal force of 4.0278 N. The average pull force is recorded at 0.46 N, leading to a frictional force of -0.46 N. The formula for the coefficient of friction (μk) is clarified as μk = Fk / N, resulting in a calculated value of -0.1142, which is incorrect as coefficients of friction cannot be negative. The negative value arises from the defined direction of forces, emphasizing the importance of consistent sign conventions in calculations. Understanding these principles is essential for accurate lab results.
timsmith98
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Homework Statement


I'm having trouble finding the coefficient of kinetic friction for a lab using spring scales.
Mass=.411kg
Normal Force=4.0278
Average Pull Force=.46N
Frictional Force= -.46N

Homework Equations


μ k = Fk / N.

The Attempt at a Solution


μ k = -.46N/4.0278
μ k = -.1142
 
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I am not entirely sure what the variable in the last part meant, it may be better if you could use subscripts to distinguish the terms. What I can say is that the coefficient of friction--μ is equal to the quotient of Friction force and normal force. So:

(Force of friction)/(Normal force) = μ

Have fun with the lab.
 
The coefficient of friction isn't going to be negative. That's just due to the direction that you defined as +ve.
 

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