Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
In the case of the cube, the pseudowork (force of friction x sliding
distance) is negative and identically equal (as it must *always* be)
to the change in the cube's bulk kinetic energy. However, since the
points of contact repeatedly break free and reestablish contact, their
effective displacements are *less* than the sliding distance. As a result,
the external work is *less* negative than the pseudowork and, therefore,
the *total* energy of the cube does not decrease by as large an amount as
does the bulk kinetic energy.