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Homework Help: Calculating work done by friction

  1. Nov 3, 2006 #1
    Hi,

    When you compress a spring and release it (allowing object to spring some distance), to compute the work done by friction, your s term in W=Fs would have to equal the distance that the spring is compressed + the additional distance traveled by the object once it leaves the spring, right?

    That's what I alwasy thought, but in one of my problems, it uses an s value that equals ONLY the distance traveled by the object after it surpasses the point of the uncompressed spring.

    Ryan
     
  2. jcsd
  3. Nov 3, 2006 #2
    Does it say the surface under the spring is frictionless?
     
  4. Nov 4, 2006 #3
    No, it does not...
     
  5. Nov 4, 2006 #4
    Do you know the initial velocity after the object is released? You could use conservation of energy to see how much EPE is converted to KE. Whats left over is the work taken out of the system by friction. Then you can add this to what you figure out later
     
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