What's the difference between normal and reaction force? Learning about forces and frictions at the moment, one things I can't seem to grasp is what is the difference between the normal and reaction force? They both act perpendicular to a surface and away from it, but what is the difference between both of these forces? I have tried searching this up on the internet to no avail unfortunately.
 A: Reaction force refers to its physical content - a response to the action of an object. Normal force refers to its direction - it is perpendicular to the surface. Many forces can be normal forces and/or reaction forces, and do not necessarily be both. The elementary physics however often uses the term normal force in a reference to the force produced by a support on an object. In this case it is both a normal (in the general sense described above) and a reaction force.
A: In mechanics the normal force is the component of a contact force perpendicular to the surface that an object contacts.
A reaction force is part of an action reaction pair of forces per Newton’s third law, snd can have components both perpendicular and parallel to a contact surface.
So a normal force can be the perpendicular component of the reaction to a force exerted by an object on a surface, but a reaction force is not necessarily a normal force.
Hope this helps
A: The reaction force acts in the opposite direction to original action, not in the perpendicular direction. If the original action is not in the perpendicular direction, neither will be reaction force (unless the surface is frictionless).
This happens for example during walking. The normal force is by definition upward and it cancels the downward gravitational force and downward push of your leg (to not fall under the surface). But you also wish to move ahead and thus you push with your leg backwards also. This gets compensated by the frictional force (so that you don't slip). The sum of the frictional force in parallel direction and normal force in upward direction is diagonal reaction force, which is the overall reaction of the surface on your leg.
A: In the context you are describing they are both the same force and indeed act in the same direction. That is, the weight force exerted by the object is directed downward and a “reaction” force, or the “normal” force acts in an upward direction.
There is no difference between the two (the "reaction" and normal) in this context. They are both terms used to describe the same thing. But remember that a reaction force is one that acts equal and opposite to another force and in general is not a perpendicular force.
