# Normal forces and walls

• B
Well, we all know that normal force is the force that keeps things from falling to the center of the earth, right? Well, that should apply to horizontal surfaces such as the ground. But does normal force work for vertical and diagonal forces such as a wall, too?

Nugatory
Mentor
Any time something is pressing on a surface, no matter what the angle of the surface, there is a normal that is perpendicular to the surface. If you're leaning against a wall, you are held in place by the vertical normal force from the floor (which stops you from falling to the center of the earth) and the horizontal normal force from the wall (which stops you from tipping over even though you aren't standing straight).

Lie flat on an inclined plane and the normal force will be perpendicular to the surface of the plane, neither horizontal nor vertical.

Any time something is pressing on a surface, no matter what the angle of the surface, there is a normal that is perpendicular to the surface. If you're leaning against a wall, you are held in place by the vertical normal force from the floor (which stops you from falling to the center of the earth) and the horizontal normal force from the wall (which stops you from tipping over even though you aren't standing straight).

Lie flat on an inclined plane and the normal force will be perpendicular to the surface of the plane, neither horizontal nor vertical.

And normal forces from walls prevent something from falling through the walls, right?

anorlunda
Staff Emeritus
And normal forces from walls prevent something from falling through the walls, right?
Yes, sort of.

But it sounds like you are missing the significance of the word normal.

Definition of normal
1:perpendicular; especially :perpendicular to a tangent (see 1tangent 3) at a point of tangency

Yes, sort of.

But it sounds like you are missing the significance of the word normal.

Definition of normal
1:perpendicular; especially :perpendicular to a tangent (see 1tangent 3) at a point of tangency

Honestly, I never saw the perpendicular definition of normal before.

Chestermiller
Mentor
The words normal and perpendicular are synonyms.