Analog information is the correct answer.
The momentum of an object is the product between the mass m of the object and its velocity:

The truck in our problem has momentum equal to
and a mass of

so, if we re-arrange the previous formula, we can use these data to find the velocity of the truck:
In free fall, the only force acting on an object is gravity. The force of gravity is an unbalanced force, which causes an object to accelerate. In the absence of air, two objects with different masses fall at exactly the same rate of acceleration.