question_answer

If \[{{\mu }_{r}},\] \[{{\mu }_{k}}\] and \[{{\mu }_{s}}\] represent the coefficients of rolling friction, kinetic and static friction, then

A) \[{{\mu }_{r}}={{\mu }_{s}}={{\mu }_{k}}\]  

B)        \[{{\mu }_{r}}>{{\mu }_{k}}>{{\mu }_{s}}\]

C) \[{{\mu }_{r}}<{{\mu }_{s}}<{{\mu }_{k}}\]              

D) \[{{\mu }_{r}}<{{\mu }_{k}}<{{\mu }_{s}}\]