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Force and Motion(HELP ME)

  1. Nov 30, 2011 #1
    1. The problem statement, all variables and given/known data
    A ball is rolling on a rough horizontal surface with a deceleration of 2m/s(square). Find the coefficient of kinetic friction between the ball and the surface?

    2. Relevant equations

    f(k) = u(k)N

    3. The attempt at a solution
    u(k) = fk/N
    i use 2/10
    my answer is 0.2

    i think my answer is wrong. help me!!!!
  2. jcsd
  3. Nov 30, 2011 #2
    Please supply all known data, i.e. Mass of the ball?
  4. Nov 30, 2011 #3
    There are no mass. I am stuck with this qn. I have no idea how to start
  5. Nov 30, 2011 #4
    You cannot calculate kinetic friction without mass.
  6. Nov 30, 2011 #5
    it dun have mass for this qn. How? Can i able to use w = mg
  7. Nov 30, 2011 #6
    Does it tell you the normal force? From where are you getting the 10?
  8. Nov 30, 2011 #7
    No. It didn't tell me the normal force. I use g = 10ms(-2 square) g is the gravitational acceleration
  9. Nov 30, 2011 #8
    I am at a loss, it seems you need more data, because without the mass of the ball you don't know the force of friction or the normal force, which are both required to find the coefficient of friction, as far as I know
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