Understanding Newton's 3rd Law: Reactionary Forces to Friction

[sarm2005]

Ok so you push a box forward and the box exerts a force of friction backwards


Would the reactionary force to the friction on the box (the ground pushing the box backwards) be the force of the box pushing the ground forwards

 

[jae05]

yea. that's given by N3L. but it's much more conveinent to think in terms of F_{fric}=\mu N. calculating the entire shift of the Earth everything we want to do a frictional problem's a bit of a stretch :D

 

[sarm2005]

I wasn't actually trying to calculate it. Just making sure I understand Newton's 3rd law.