Question

Vă rog exercițiul acesta

Answer 1

[tex]Rezolvare:\\ d1= \frac{1}{3} d= \frac{5}{15} d\\ d2= \frac{2}{5} d= \frac{6}{15} d\\ d3=d-\frac{5}{15} d-\frac{6}{15} d=\frac{4}{15} d\\ vm= \frac{d}{t}(1)\\ t=t1+t2+t3\\ t= \frac{d1}{v1} +\frac{d2}{v2}+\frac{d3}{v3}\\ t= \frac{5d}{15v1} + \frac{6d}{15v2}+ \frac{4d}{15v3} \\ t= \frac{5dv2v3+6dv1v3+4dv1v2}{15v1v2v3}\\ t= \frac{d(5v2v3+6v1v3+4v1v2)}{15v1v2v3} (2)\\ Inlocuim(2)in(1)\\ vm= \frac{d}{ \frac{d(5v2v3+6v1v3+4v1v2)}{15v1v2v3} } \\ vm= \frac{15v1v2v3}{5v2v3+6v1v3+4v1v2} \\ [/tex]