Question

an object of mass 4 kg is placed on an inclined plane at an angle of 60. if the object slides down the plane with an acceleration of 3m/s, what is the coefficient of the kinetic friction

Answer 1

The forces on the  y axis are:

N-mgcos(60)=0   , wich becomes

N=mgcos(60)

Rember that the friction force is always contrary to the motion of an object and its formula is  f=μ * N

The forces in the x axis are:

-f + mgsin(60)= m * a

-μ*mgcos(60) + mgsin(60)=m*a  ,

μ = ( m*a - mgf=μ[sin(60) )/ ( mgcos(90) )