[tex]v_1=70\ km/h\\v_2=80\ km/h\\t=2h\\\\v=\frac{s}{t}\to s=vt\\\\s_1=70\ km/h\cdot2h=140\ km\\s_2=80\ km/h\cdot2h=160\ km\\\\look\ at\ the\ picture[/tex]
[tex]218^2=140^2+160^2-2\cdot140\cdot160\cdot cos\alpha\\\\47524=19600+25600-44800cos\alpha\\\\47524=45200-44800cos\alpha\\\\44800cos\alpha=45200-47524\\\\44800cos\alpha=-2324\ \ \ \ /:44800\\\\cos\alpha\approx-0.051875\Rightarrow\alpha\approx92^o58'[/tex]
