If a #1 kg# object moving at #14 m/s# slows down to a halt after moving #7 m#, what is the coefficient of kinetic friction of the surface that the object was moving over?
1 Answer
Solve for
Explanation:
We can use the work energy theorem, which states that the net work done is equal to the change in Kinetic Energy:
Now with
Now let's draw a Free Body Diagram:
From FBD we see that the horizontal force slowing the object is the force of friction acting in the opposite direction of motion. And knowing that
Solve for
excessive. What went wrong? Well the general approach is correct but the assumption that friction is the only one consuming energy in slowing the object may not be correct. One can argue Heat and Sound will also take energy away lowering the energy available for friction and hence approaching a reasonable answer of