[latex]s_{1}=100km \ s_{2}=40km \ t_{1}=80min=1 frac{1}{3} h= frac{4}{3} h \ t_{2}=30min= frac{1}{2} h[/latex] Średnia prędkość to droga podzielona przez czas potrzebny do przebycia tej drogi a) [latex]v_{s1}= frac{s_{1}}{t_{1}} = frac{100km}{ frac{4}{3} h} = frac{100km*3}{4h} =75 frac{km}{h} [/latex] [latex]v_{s2}=frac{s_{2}}{s_{1}}= frac{40km}{ frac{1}{2} h} =80 frac{km}{h} [/latex] b) [latex]v_{s}= frac{s_{1}+s_{2}}{t_{1}+t_{2}} [/latex] [latex]v_{s}= frac{100km+40km}{ frac{4}{3} h+ frac{1}{2} h} = frac{140km}{ frac{11}{6} h} approx 76,4 frac{km}{h} [/latex]
[latex]s_1 = 100km\ s_2 = 40km\ t_1 = 80min = 1 frac{1}{3} h\ t_2 = 30min = frac{1}{2} h \\ V_{s1} = frac{100km}{1 frac{1}{3}h} = 100km * frac{3}{4h} = 75 frac{km}{h}\ V_{s2} = frac{40km}{frac{1}{2}h} = 40km * frac{2}{h} = 80 frac{km}{h}\ \ t_c = 80min+30min = 110 min = 1frac{5}{6}h\ S_c = 100km + 40 km = 140km\\ V_c = frac{S_c}{t_1+t_2} = frac{S_c}{t_c}\ V_c = frac{140km}{1frac{5}{6}h} = 140km * frac{6}{11h} = frac{840}{11}frac{km}{h} = 76,4frac{km}{h}[/latex]
