Normal Force vs. Newton's Third Law of Motion

[Allemande135]

What's the difference between the Normal Force and Newton's Third Law of Motion? Because they sound pretty similar.

[King112]

Normal Force is a perpendicular force (refer attached sketch). It is perpendicular to the surface, even if it's on a  slope (again sketch).

 

The Third law states that every action has an equal and opposite reaction. So in some cases, the normal force can be the force mentioned in the third law, but not always. 

 

In the example attached, the normal force is perpendicular to the surface (indicated by the solid arrow). The ball is rolling down a slope, and the force described by Newton's third law is Friction (indicated by the dotted arrow with the "Third Law" label)

 

I hope this helps (and is right; not studied physics since I graduated 2 years ago)

 

[kw0573]

I can talk a bit more about Newton's Third law, specifically, it connects two forces i) APPLIED TO TWO DIFFERENT OBJECTS ii) in opposite directions iii) with equal magnitude. Every force has a force described by this Law (but it gets weird when discussing magnetic forces, or when you consider 'forces' causing the universe to expand.)

The Newton's Third Law applied to Earth pulling you down, is actually you pulling Earth up!

The most common place this Law is particularly useful in explaining everyday phenomena is when it applies to friction. You know how on icy, or very low friction conditions, you can hardly control the movement? The reason we can walk, or drive, is that we apply a backward friction force on the ground, so the ground applies a forward friction force on us. This is why @King112 draw Third Law perpendicular to normal force, because in this plane it is most useful. In that diagram, the Third Law force of the normal force is the object pushing on the ground (as opposed to the force of ground pushing on the object)