# Homework Help: Mu without Ff

1. Oct 20, 2009

### ConfusedPupil

1. The problem statement, all variables and given/known data
We are doing a lab nearly verbatim to the one at this link, http://dev.physicslab.org/Document.aspx?doctype=2&filename=Momentum_InelasticCollisionsSoftball.xml" However, under #6 in data and procedure I had forgotten to measure frictional force. Is there anyway to find mu or force of friction using the mass of the ball, initial velocity, time in air, distance thrown form box, mass of box and packaging, Fn, and box displacement?

2. Relevant equations
Inelastic collision formula
momentum formulas

3. The attempt at a solution
N/A stumped without formula to find mu or Ff, data not collected so I don't know how to work the real problem which I can do otherwise. Vf could also help me find Mu by using (0.259kg(vf-0m/s/0.63s))/2.54N = mu

Last edited by a moderator: Apr 24, 2017
2. Oct 20, 2009

### Delphi51

You can find mu if you can take a bit of cardboard to a floor surface similar to the one you used in the experiment. Put any known mass on the cardboard and pull it along the floor with a force scale. If you can't get your hands on a scale, use an elastic band, measure its stretch, then find some way to achieve that same stretch with known forces. Likely you can look up the mass of coins and calculate their mg if no easier method comes to mind!

3. Oct 20, 2009

Thanks