For this case, the first thing you should do is take into account the definition of normal force.
By definition, we have:
- The normal force is that which is exerted on an object that is perpendicular to the surface.
If we define the coordinate system as:
- Horizontal axis points to the right
- Vertical axis points up
Then An object resting on a wall can have normal force in a horizontal direction.
Answer:
The normal force is perpendicular to the surface. The direction can be horizontal. Example: an object on a wall.
