HELP ME PLEASE. nie rozumiem fizyki w ogóle, a zadanie trzeba zrobić. Będę bardzo wdzięczna

 I odcinek : ruch jedn. przyspieszony :  s = 125 m Vo = 0  Vk = 25 m/s t₁ =  ? [latex]s = Vot + frac{at^2}{2 } ............. extgreater Vo = 0 [/latex] [latex]s = frac{at^2}{2 } [/latex] [latex]a = frac{V_k - Vo}{t } ............. extgreater Vo = 0 ........... extgreater a = frac{V_k}{t } [/latex] [latex]s = frac{ frac{V_k}{t} * t^2}{2 } = frac{V_k * t }{2 } /* 2 2s = V_k * t / : V_k [/latex] [latex]t = frac{2s }{V_k } [/latex] [latex]t_1 = frac{2 *125 m }{25 frac{m}{s} } = 10 s [/latex] II odcinek : ruch jednostajny V = 25 m/s s₂ = 400 m t₂ = ? V = s₂ /t₂ t₂ = s₂/ V t₂ = 400 m /25 m/s = 16 s odcinek III : ruch jedn. opózniony s₃ =  200 m Vo[latex]s = Vot - frac{at^2}{2} [/latex]₃ = 25 m/s Vk = 0 m/s [latex]a = frac{Vk - Vo }{t } ,............ extgreater Vk = 0 ............. extgreater a = frac{-Vo}{t} [/latex] [latex]s = Vot - frac{ frac{Vo}{t} *t^2}{2} = Vot - frac{V_o * t }{2 } = frac{2Vot - Vot }{2} = frac{Vot}{2} [/latex] [latex]s_3 = frac{Vo_3 * t_3 }{2 } /* 2 2s_3 = Vot_3 /:Vo[/latex] [latex]t_3 = frac{2s_3}{V_o_3} [/latex] [latex]t_3 = frac{2 *200 m }{25 frac{m}{s} } = 16 s [/latex] t = t₁ + t₂ + t₃ t = 42 s