What is a Normal force and how does it work?

Question

I understand that if an object sits on a table, the Normal force presses against the bottom to cancel out the force of gravity from above, and that the Normal force will increace to account for additional forced on the object from above (e.g. a person pressing on it)...

but how/why does this occur? It seems so obvious that it eludes me....

thanks :)

Answer 1

It occurs because the object does not deform. "Normal" is a mathematical term that refers to the fact that this force can only be exerted perpendicular (more precisely, normal) to the surface. If you imagine a slab of clay and set something heavy on it, the surface deforms, meaning that the clay could not supply enough force normal to the surface to prevent the object from sinking in, or that Fn

Answer 2

the conventional reaction is created via sturdy products subjected to any tension interior right here way. observe that it is not correct how the tension is utilized. Any of your forces and relatively some greater all reason the comparable elementary technique ) a) initially some tension is utilized to an infinitesmally smalll component to a floor. This factor has negligible mass and intensely few atomic bonds. b) this small section quickens and strikes in the direction of the tension. c) by using fact the exterior is deformed the quantity of the exterior section in "touch" with the tension will strengthen. observe this does not inevitably mean actual touch. it would desire to be greater advantageous pronounced as "laid low with the utilized tension" d) this greater advantageous section has increasing mass and to accomplish that place many greater bonds have had to be stretched via ever greater advantageous quantities. observe too that whether we are handling sub atomic debris then there is probably no longer bonds however the distortion to the particle nevertheless creates the comparable result. e) those stretched bonds are performing in an identical thank you to springs so as that they are opposing the utilized tension. f) faster or later the resisting forces are precisely equivalent to the utilized forces and the exterior of the textile stops accelerating. stable state is performed. the stairs above word to something no rely how small. Forces would reason preliminary acceleration of a few factor of the article they're utilized to however the circulate of that factor motives distortion that for the duration of turn motives the conventional reaction. subsequently for any merchandise "each and every action has an equivalent and opposite reaction" And in any respect circumstances the reaction tension would desire to equivalent the utilized tension. observe additionally that even in quantum mechanics, the place one particle would tunnel via yet another the innovations do no longer regulate. If some thing tunnels via without interplay then no tension has been utilized so no popular reaction has took place. whether you're taking some thing that's no longer sturdy. as an occasion a gas or a liquid, you ought to use each and every of the stairs above to make certain the place the conventional reaction would desire to stand up. At a very small point issues circulate internally changing the form. the two you get resisting forces F = ma for the parts that are shifting in the physique or you have the entire physique in some way incapable of shifting and consequently offering the reaction tension.