the complete question in the attached figure
we have that
d=0.51 mm------------------------- >0.00051 m
v = √(2ad) = √(2 * 1300m/s² * 0.00051 m) = 1.15 m/s initial velocity
a=9.8 m/s²
Then d = v² / 2a = (1.15m/s)² / (2*9.8) m/s² = 0.059 m = 59 mm
the answer is 59 mm