How can I determine the initial velocity of a ball thrown towards a ceiling?

[ashlee.m]

Homework Statement

a ball that is 10cm in diameter is thrown 2.4m above the level of hands vertically to reach a ceiling what is the initial velocity

Homework Equations

struggling to determine the intial velocity as have no time

The Attempt at a Solution

Help! really struggling

 

[da_nang]

Assuming there is no air resistance, then use the conservation of energy principle.

 

[Rbraind]

conservation of energy principle?
I have a similar problem and stuck too. I'm thinking if the down part of the balls flight equals the same as the up part then I was thinking you can work out the second half of the flight with vf2 = vi2 + 2ad, knowing the initial velocity for the return trip is 0m/s and acceleration is gravity and d=2.4m. Not sure if I'm on the right track though. But if so then can use one of the formulas with time the only missing variable and work it out.