I don't have a picture of this situation so I will do my best to describe it in words. If we have a box that's "swinging" in a circular motion at the end of a string, but at the same time the box is experiencing a frictional force due to it's brushing against another object. The picture in my book shows a box on a tabletop that's being moved in a centripetal motion due to the actions of a string while at the same time it's experiencing a frictional force from the table. The question wants to know the direction of the net force at a certain point.
F(net) = sum of all forces
The Attempt at a Solution
I assumed that at any given point on the "circle of motion" the net force should be pointing inward towards the center of the circle, after all that's the direction of the acceleration. The correct answer given is that the net force is a combination of the frictional vector and centripetal vector. This makes absolutely no sense to me. If the net force wasn't going inwards towards the center of the circle then the object wouldn't move the way it is. Thanks for any help.