1. The problem statement, all variables and given/known data The attachment shows a simple diagram of a system consisting of a Sphere(uniform) and and rod(uniform) in equilibrium. The rod is in rough contact with the sphere and hence there would be friction (acting vertically at the point of contact of the two objects). Both objects rest on a horizontal rough ground so that the friction acting on the rod is F and the frictional force acting on the sphere is -F . Both will have the same magnitude because the system is in equilibrium. The normal force N is also present at the point of contact. 3. The attempt at a solution Here is the problem Resolving horizontally for the rod only should give us the result that N=F. Is that true or false ? If false, then is it wrong to resolve for just one object among the two ?