Physics

Problem

A wooden block rests on three different rough horizontal surfaces having coefficients of static friction

0.2

0.4

and

0.6

respectively. Arrange the corresponding angles of friction in ascending order. a)

\phi_{0.6} < \phi_{0.4} < \phi_{0.2}

\phi_{0.2} = \phi_{0.4} = \phi_{0.6}

\phi_{0.2} < \phi_{0.4} < \phi_{0.6}

\phi_{0.4} < \phi_{0.2} < \phi_{0.6}