Question

A block of mass m slides down and inclinded plane of inclination theta with uniform speed. the coefficient of friction between the block and the plane is mu. the contact force between the block and the plane is

Answer 1

Let mass be m. The required to lift it is F2=mgF2=mg
F1F1=force required to drag it along the plane
f1=mgsinθ+μmgcosθf1=mgsin⁡θ+μmgcos⁡θ
F1mgsinθ+μmgcosθμ<1−sinθcosθμ<1−sin⁡θcos⁡θ
μ<1−sin30cos30μ<1−sin⁡30cos⁡30
μ<13–√