[tex]v_1 = 72 \frac{km}{h}=20\frac{m}{s}\\\Delta t = 5s\\a = 1,5\frac{m}{s^2}[/tex]
[tex]a = \frac{\Delta v}{\Delta t} = \frac{v_{koncowe}-v_{poczatkowe}}{\Delta t}= \frac{v_x-v_1}{\Delta t} \\ \\a*\Delta t =v_x-v_1\\v_x=a*\Delta t +v_1=1,5\frac{m}{s^2}*5s+20\frac{m}{s}=27,5\frac{m}{s}[/tex]
