using V²=u² +2gH
let's assume the ball falls from rest, then it's initial velocity = 0ms-¹ (U=0)
then from the above info V= 35ms-¹
g= 10ms-² (value of acceleration due to gravity to the nearest tens)
so input your values above into the given formula to find height
35² = 0² +2×10×H
1225 = 20H
H = 1225÷20 = 61.25m