DANE: [latex]s_1=4km[/latex] [latex]V_1=20 frac{km}{h}[/latex] [latex]s_2=6km[/latex] [latex]V_2=20 frac{km}{h}[/latex] ROZWIĄZANIE: [latex]V= frac{s}{t} [/latex] [latex]t_1= frac{s_1}{V_1}= frac{4km}{20 frac{km}{h} } =0,2h[/latex] [latex]t_2= frac{s_2}{V_2}= frac{6km}{20 frac{km}{h} } =0,3h[/latex] [latex]t=t_1+t_2=0,2h+0,3h=0,5h[/latex] [latex]s=s_1+s_2=4km+6km=10km[/latex] [latex]V_{sr}= frac{s}{t}= frac{10km}{0,5h}=20 frac{km}{h} [/latex]
dane: s₁ = 4 km v₁ = 20 km/h s₂ = 6 km v₂ = 20 km/h szukane: v(śr) = ? ./. [latex]v_{sr} = frac{s_{c}}{t_{c}}\s_{c} = s_1 + s_2\ t = frac{s}{v}\s_{c} =frac{s_1}{v_1}+frac{s_2}{v_2} \\v_{sr}= frac{s_1+s_2}{frac{s_1}{v_1}+frac{s_2}{v_2}}=frac{s_1+s_2}{frac{s_1v_2+s_2v_1}{v_1v_2}}=frac{v_1v_2(s_1+s_2)}{s_1v_1+s_2v_2}}\\v_{sr} = frac{20*20(4+6)}{4*20+6*20} =frac{4000}{200} [frac{km}{h}]\\v_{sr} = 20frac{km}h} [/latex]
