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Coefficient of friction formulas help

  • Thread starter Kdawg
  • Start date
  • #1
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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?
 

Answers and Replies

  • #2
32
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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,
[TEX] F = {\mu}_s * N [/TEX]
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:
  • #3
Notice that the body is moving with uniform accelaration.
This means that the net force acting on the body is 0.
Therefore, [tex]\mu * 52 N = 36 N[/tex]
This gives, [tex]\mu = 36 / 52[/tex]
 
  • #4
brewnog
Science Advisor
Gold Member
2,711
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The body is moving with uniform *velocity*, not acceleration, otherwise the net force on the body would not be zero.
 

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