PE at the top should be equal to the KE at the bottom becausethere is no friction

\(\displaystyle{\frac{{{1}}}{{{2}}}}{\left({m}{V}^{{2}}\right)}={m}{g}{h}\)

\(\displaystyle{V}=\sqrt{{{\left({2}{g}{h}\right)}}}=\sqrt{{{\left({2}\times{9.8}\times{150}\right\rbrace}={54.22}\ \frac{{m}}{{s}}}}\)

\(\displaystyle{\frac{{{1}}}{{{2}}}}{\left({m}{V}^{{2}}\right)}={m}{g}{h}\)

\(\displaystyle{V}=\sqrt{{{\left({2}{g}{h}\right)}}}=\sqrt{{{\left({2}\times{9.8}\times{150}\right\rbrace}={54.22}\ \frac{{m}}{{s}}}}\)