Doubt & Answer Explanation

Answer Explanation

Most dry materials in combination have friction coefficient values between 0.3
and 0.6. Values outside this range are rarer, but teflon,
for example, can have a coefficient as low as 0.04. A value of zero would mean
no friction at all, an elusive property – even magnetic levitation vehicles have drag. Rubber in contact
with other surfaces can yield friction coefficients from 1 to 2. Occasionally it
is maintained that µ is always < 1, but this is not true. While in most
relevant applications µ < 1, a value above 1 merely implies that the force
required to slide an object along the surface is greater than the normal force
of the surface on the object. For example, silicone rubber or acrylic rubber-coated surfaces have a
coefficient of friction that can be substantially larger than 1.