[tex]\displaystyle\bf\\\\Se~da:\\m=2Kg\\V=constant~pe~o~suprafata~orizontala.\\\mu=0,\!2\\\\Lu\u am:\\g=10\\\\Se~cere:\\a)~F_f=?~~(forta~de~frecare)\\b)~F_t=?~~(forta~de~tractiune)\\\\Rezolvare:\\\\G=mg=2\times10=20~N\\\\N=G=20~N\\\\a)~F_f=\mu N=0,2\times 20=\boxed{\bf4 N}\\\\b)F_t=F_f=\boxed{\bf4 N}~~~~(deoarece~V=constant)[/tex]