Q93
How fast does a person fall? I can't find the rules!
I don't think the rules explicitly say how fast a person in free fall falls, but it does mention at least two situations that are close enough and are probably reasonable.
If you don't want to use those rulings (150 ft. in the first round, 300 ft. per round thereafter), you can always just calculate it. One round is equivalent to 6 seconds. Assuming normal Earth gravity on the world you're playing in, acceleration from gravity is 9.8 m/s^2, or roughly 32 ft/s^2.
d(6s) = 1/2 * a * t^2 = 576 ft. in the first round. Falling distance would be ~1100 ft. more in the second round due to reaching terminal velocity.
150 ft. in the first round is actually reasonable as given the abstraction of turn-based movement, especially with forced movement like bull-rushes off the side of a cliff, a character can be assumed to only have fallen for half the time of the first round that it was seemingly falling (the other half of the round, said character would have been on solid ground in the moments leading up to sudden loss of ground beneath its feet).