what is an example of normal force?

Answer 1

Normal to the surface force or simply normal force is a force directed at 90 degrees to the surface.

And object laying on the horizontal surface exerts a normal force equal to int weight

N=mg

And object laying on the inclined surface exerts a normal

force equal to int weight times a cosine of the angle A the surface makes with the horizontal

N= mg cos(A)

...and so on.

Answer 2

The normal force is zero whenever the perpendicular force between an object and the surface it's touching is zero. (Note that the surface does not need to be horizontal.) kuiperbelt2003 provided the easiest example. Another example is when a car or roller coaster goes upside down around a loop-de-loop at just the right speed. If you adjust the speed correctly, you can get the normal force (track pushing down against car) to be zero at the moment the car is upside down. (Note: in real roller coasters, this is dangerous, so they go fast enough to keep the normal force at a nonzero value.)

Answer 3

Punch the wall and you can feel pain in your first. Jump off a rock onto the ground and you will feel the sharp pain in your ankles. You apply force to the wall and the force applies a force normal back to you. Same applies for the ground