Question

If ${\mu }_s,{\mu }_k$ and ${\mu }_r$ are coefficient of static friction, sliding friction and rolling friction , then

• A. ${\mu }_s<{\mu }_k<{\mu }_r$
• B. ${\mu }_k<{\mu }_r<{\mu }_s$
• C. ${\mu }_r<{\mu }_k<{\mu }_s$
• D. ${\mu }_r={\mu }_k={\mu }_s$

Answer 1

The correct option is C ${\mu }_r<{\mu }_k<{\mu }_s$

${\mu }_r<{\mu }_k<{\mu }_s$

which implies that the rolling friction is least because of the wheel and rotating effect and the kinetic friction is in middle of the series because of its moving properties & static friction is highest because of the limiting moving properties.