Question

A15N crate rests on an ramp , the maximum angle just before it slips is 25 degree with the horizantle , what the coefficient of static friction between the crate and ramp surfaces ?

Answer 1

ma=mgsinα-F(fr)=mgsinα-μN=
=mgsinα-μmgcosα

μ(stat.fr) => a=0

0= mgsinα-μmgcosα
μ=tanα