4. Can we reduce friction to
zero by polishing surfaces or
using large amount of
lubricants?
5. Friction can never be
entirely eleminated. No
surface is perfectly
smooth. Some
irregularities are always
there.
6.
7.
8. When one body rolls over
the surface of another body,
the resistance to its motion is
called “Rolling friction”
Since the rolling friction is
smaller than the sliding
friction, sliding is replaced in
most machines by rolling by
the use of ball bearings.
