Answer:
47 ms
well the time it takes to fall 100m is the same time it takes to travel 65m horizontally.
The time to fall vertically, t is sqrt(2d/g). [this comes from d = 1/2at^2]
so t = sqrt(2*100/9.8) = 4.52s.
The vertical speed at that time is g*t = 9.8*4.52 = 44.3m/s
The horizontal speed is the horizontal distance over the same 4.52s, = 65/4.52 = 14.4m/s.
so the final velocity is = sqrt(44.3^2 + 14.4^2) = 47.ms