[tex]h_1=5m \\ h_2=10m[/tex]
a) Conservarea energiei:
[tex]mgh_1+\dfrac{mv^2}{2}=mgh_2 \\ \\ \Rightarrow v=\sqrt{2g(h_2-h_1)}.[/tex]
b) [tex]v_0=12m/s[/tex]
Conservarea energiei:
[tex]mgh_1+\dfrac{mv_0^2}{2}=mgh_2+\dfrac{mv^2}{2} \\ \\ \Rightarrow \dfrac{v^2}{2}=g(h_1-h_2)+\dfrac{v_0^2}{2} \\ \\ \Rightarrow v=\sqrt{2g(h_1-h_2)+v_0^2}.[/tex]