V=S/T V=7m/s / 0,5 s V= 14 m
[latex]E_{m}^{a}=E_{m}^{b} \ mgh+ frac{mV_{x}^{2}}{2}=frac{mV^{2}}{2} \ mV^{2}-2mgh=mV_{x}^{2} \ [/latex] [latex]V_{x}^{2}=V^{2}-2gh \ h=V_{x}t+frac{gt^{2}}{2} \ V_{x}^{2}=V^{2}-2g(V_{x}t+frac{gt^{2}}{2} ) \ V_{x}^{2}=V^{2}-2gV_{x}t-g^{2}t^{2} \ [/latex] [latex]V_{x}^{2}+2gV_{x}t+g^{2}t^{2}-V^{2}=0 \ Delta=4g^{2}t^{2}-4g^{2}t^{2}+4V^{2}=4V^{2} \ sqrt{Delta}=|2V|=2V \ D_{V_{x}}: V_{x} in <0; + infty) \ [/latex] [latex]V_{x_{1}}=frac{-2gt-2V}{2} ot in D \ V_{x_{2}}=frac{-2gt+2V}{2}=frac{-2 cdot 10 cdot 0,5+2 cdot 7}{2}=frac{14-10}{2}=frac{4}{2}=2 frac{m}{s} in D[/latex] i mamy prędkość wyrzutu ------------------------------------------------------------------ wysokość rzutu: [latex]frac{mV_{k}^{2}}{2}=mgh \ h= frac{V_{k}^{2}}{2g}=frac{49frac{m^{2}}{s^{2}}}{20 frac{m}{s^{2}}}=2,45m[/latex]
