[latex]dane:\s = 20[m]\a = 10[ frac{m}{s^2}]\\Szukane :\v_k = ? \\Rozwiazanie :\a = frac{Delta v}{Delta t} /cdot Delta t\Delta v = a cdot Delta t \\s = frac{1}{2}at^2 /cdot 2 \2s = at^2 /:a \t^2 = frac{2s}{a} /: sqrt{} \t = sqrt{ frac{2s}{a} } \\\\t = sqrt{ frac{2cdot 20}{10} } = sqrt{4} = 2 [s] \\\Delta v = 10 cdot 2 = 20 [frac{m}{s} ] \\Delta v = v_k = 20[ frac{m}{s} ][/latex]
[latex]dane:\h = 20 m\g = 10frac{m}{s^{2}}\szukane:\v = ?[/latex] Z zasady zachowania energii: [latex]E_{p} = E_{k}\\mgh = frac{mv^{2}}{2} |*frac{2}{m}\\v^{2}=2gh\\v = sqrt{2gh} = sqrt{2*10frac{m}{s^{2}}*20m}} = sqrt{400} frac{m}{s}\\v = 20frac{m}{s}[/latex]
