Answer:
Explanation:
To know the force down you need to divide the force into two components X parallel with the inclined surface and Y, the perpendicular one.
F= m* g= 7kg*9,8m/s^2= 68.6 N
Fy= F*cos(30) = - N
Fx= F*sen(30)
N = normal. Force which is perpendicular to the movement equal and opposite to weigh in the plane.
Friction force = Fr= Coef *N
In the inclined there're Fx to one side and Fr to the other side. Perpendicular to it there are Fy and N
