Given that the airplane starts from the rest (this is initial velocity equals to zero) and accelerates at a constant rate, position can be described like this: where x is the position, t is the time a is the acceleration and is initial velocity. In this way acceleration can be found. .
Now we are able to found velocity at any time with the formula:
We use conservation of energy. Note that at the beginning of the drop, the pig has only potential energy, and at the bottom, it has only kinetic energy. Then: