Answer
$y =-77.6m$
Work Step by Step
A positive value is in the upward direction while a negative one is in the negative direction for the vertical distance ($y$)
$v^2_{_y} = v^2_o{_{_y}} - 2gy$
$2gy = v^2_o{_{_y}} - v^2_{_y}$
$y = \frac{v^2_o{_{_y}} - v^2_{_y}}{2g}$
$y = \frac{52^2_{m/s} -65^2_{m/s}}{2\times 9.8_{m/s^2}}$
$y =-77.6m$
