Answer:
About half way through its fall
Step-by-step explanation:
Firstly, let's talk about the thermal energy - we can pretty much disregard it because of how miniscule it is compared to the rest and because it's not VERY connected to the process of falling down.
m - mass
v - velocity
g - gravitational acceleration constant (~9.81m/s^2)
Ek - kinetic energy
Ep - potential energy
The kinetic energy is dependent on the velocity - the faster an object moves, the bigger its kinetic energy. In the classic model Ek = mv^2/2
The potential energy is dependent on the altitude - the higher the object is located, the longer it'll be able to fall down. In the classic model Ep = mhg
The process of falling converts the potential energy to kinetic energy - notice that as something falls down, the altitude is rapidly reduced (and so is the potential energy) but the velocity is rising (and so the kinetic energy).
When the ball is in your hand, it's static, so v = 0, so the kinetic energy is
Ek = mv^2/2 = m*0^2/2 = 0.
When the ball hits the ground, it's altitude is 0, so its potential energy is
Ep = mhg = m*0*g = 0.
When it has stopped moving at all, again its v = 0, so the kinetic energy is 0.
Mid fall, it's still got a ways to go, so its potential energy is positive, it also has some velocity, so its kinetic energy is also positive. "About halfway through the fall" is a very acceptable answer here.