Question

A 2kg block is pulled with uniform speed up a plane which makes 30° with the horizontal force of 15 N which is parallel to the plane. Find the coefficient of kinetic friction between the block and the plane

Answer 1

$µ_k = \frac{f_k}{ N}\\ µ_k= \frac{mg sin α − ma}{ mg cos α}\\ µ_k= - tan α − \frac{a}{ g cos α}\\ µ_k= -tan α − \frac{\frac{F}{ m}}{ g cos α}\\ µ_k= - tan30 − \frac{\frac{15}{ 2}}{ 9.8 cos 30}\\ µ_k= - -0.306349\\ µ_k= 0.306349$