Coefficient of friction formulas help

AI Thread Summary
To find the coefficient of sliding friction between the sled and the sidewalk, use the formula F = μ * N, where F is the horizontal force (36 N) and N is the normal force (52 N). Since the sled is moving at a constant speed, the net force is zero, indicating that the forces are balanced. This leads to the equation μ * 52 N = 36 N, allowing for the calculation of μ. The resulting coefficient of friction is μ = 36 / 52. Understanding these principles is essential for solving similar physics problems.
Kdawg
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A 52-N sled is pulled across a cement sidewalk at a constant speed. A horizontal force of 36 N is exerted. What is the coefficient of sliding friction between the sidewalk and the metal runners of the sled?
What formulas would I use in this problem?
 
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Kdawg said:
A 52-N sled is pulled across a cement sidewalk at a constant speed. A horizontal force of 36 N is exerted. What is the coefficient of sliding friction between the sidewalk and the metal runners of the sled?
What formulas would I use in this problem?


It is simple !
Use the formula,
F = {\mu}_s * N
where F is the horizontal force and N is the normal force, which is equal to the weight of the sled. (I assume that the cement sidewalk is placed horizontally).
 
Last edited:
Notice that the body is moving with uniform accelaration.
This means that the net force acting on the body is 0.
Therefore, \mu * 52 N = 36 N
This gives, \mu = 36 / 52
 
The body is moving with uniform *velocity*, not acceleration, otherwise the net force on the body would not be zero.
 

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