[tex]h=14 \ m \\ m=350 \ kg \\ t=20 \ s \\ g=10 \ N/kg \\ L=F \cdot h; \ \ F=G=m \cdot F=350 \ kg \cdot 10 \ N/kg=3 \ 500 \ N \\ L=3 \ 500 \ N \cdot 14 \ m =49 \ 000 \ J \\ \Rightarrow \boxed{\bold{L=49 \ kJ}} \\ P=\frac{L}{t}=\frac{49 \ 000 \ J}{20 \ s}=2 \ 450 \ W \\ \Rightarrow \boxed{\bold{P=2,45 \ kW}}[/tex]