[tex]s_1 = s_2 = s = 400 \ m\\t_{M} = 1 \ min = 60 \ s\\t_{T} = 72 \ s\\\Delta v = ?[/tex]
[tex]v = \frac{s}{t}\\\\v_{M} = \frac{s}{t_{M}} = \frac{400 \ m}{60 \ s} = 6,(6)\frac{m}{s}\\\\v_{T} = \frac{s}{t_{T}} = \frac{400 \ m}{72 \ s} = 5,(5)\frac{m}{s}[/tex]
[tex]\Delta v = v_{M}-v_{T} \\\\\underline{\Delta v = 6,(6)-5,(5) = 1,(1)\frac{m}{s}}[/tex]
