Kinetic Energy

Ok, well, I'm not in AP physics, I'm in honors, but even so I need help.

In our class we are trying to get find the KE and GPE of a rubber ball (those rubber balls that's like 25 cents)

GPE = Mass x Gravity x Height
KE = 1/2 x Mass x Velocity^2

The givens were the Height, the Gravitational Pullt (we're just going to round 9.8 to 10 m/s) and the mass is 0.0235kg.

So the GPE is the one we found out pretty easily, but the KE is the tricky one mainly because of the Velocity. I should probably tell you we are dropping the ball from a free fall so we don't need a timer, however, we need to find the time to get the velocity, so we need to use the Free Fall equation in order to get that.

aaaannnd. that's where i'm stuck at. I can't seem to get the time.

wouldn't the equation be:

Dy = 1/2gt ?

and KE would be
KE = 1/2m(gt)^2?

so to get the time it would be:

(going back to the Dy equation)
t = [(1/2)g]/Dy

Since the Dy is the Height.

right?

Thanks in advance.