Hi there!
Assuming the track is frictionless:
[tex]E_i = E_f\\\\PE = KE\\\\mgh = \frac{1}{2}mv^2[/tex]
Cancel out the masses and rearrange to solve for velocity:
[tex]gh = \frac{1}{2}v^{2}\\\\v = \sqrt{2gh}\\\\[/tex]
Plug in the given height and let g = 9.8 m/s²:
[tex]v = \sqrt{2(9.8)(57)} = \boxed{33.42 m/s}[/tex]
