Difficult friction problem

  • Thread starter madman143
  • Start date
  • #1
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Homework Statement


A uniform board of length and mass lies near a boundary that separates two regions. In region 1, the coefficient of kinetic friction between the board and the surface is , and in region 2, the coefficient is . The positive direction is to the right.(Image uploaded)

Q.Find the net work done by friction in pulling the board directly from region 1 to region 2. Assume that the board moves at constant velocity



Homework Equations


Work=ForceXDistance
F=muXN


The Attempt at a Solution


i dont know ow to find F and don't know integration. So I am stuck on this problem.
Please help?
 

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Answers and Replies

  • #2
LowlyPion
Homework Helper
3,097
5
Welcome to PF.

What if you just took the average u? What would that be for the work?

It looks like the block is symmetrically moving across both regions. Starting wholly in one and ending wholly in the other.

Otherwise you can write an equation and integrate it over the distance from 0 to L.
 

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