Given data
*The given distance above the water is s = 8.40 m
*The given initial speed of the Olympic diver is u = 1.2 m/s
*The value of the acceleration due to gravity is a = 9.8 m/s^2
The formula for the diver speed, in m/s, just before she enters the water is given by the equation of motion as

Substitute the known values in the above expression as

Hence, the diver speed, in m/s, just before she enters the water is v = 12.88 m/s