Question

d= distanta
v=viteza
d/2 v1= 30 km/h
d/2 v2=15 km/ h
repede va rog​

Answer 1

[tex]d=d_1+d_2\\ d_1=d_2=\frac{d}{2}\\ t=t_1+t_2\\ t_1=\frac{d_1}{v_1}=\frac{d}{2v_1}\\ t_2=\frac{d_2}{v_2} =\frac{d}{2v_2}\\ d=v_m*t=>v_m=\frac{d}{\frac{d}{2v_1}+ \frac{d}{2v_2} }=\frac{1}{\frac{v_2+v_1}{2v_1v_2} }=\frac{2v_1v_2}{v_1+v_2}=\frac{2*30*15}{30+15}=\frac{900}{45}=20 km/h\frac{x}{y} [/tex]