an object of mass m=4.0kg , starting from rest, slides down an inclined plane of length l=3.0m . the plane is inclined by an angle of θ=30∘ to the ground. the coefficient of kinetic friction μk,1=0.2 . at the bottom of the plane, the mass slides along a rough surface with a coefficient of kinetic friction μk,2=0.3 until it comes to rest. the goal of this problem is to find out how far the object slides along the rough surface.