What is the airspeed velocity of an unladen swallow?
That would depend on the species, but the speed of an European unladen swallow is around 24 miles per hour (or 11 meters per second). This question is famously referenced in the movie Monty Python and the Holy Grail.
Suppose an European swallow is gripping a coconut by its husk, what would be its airspeed velocity?
The airspeed velocity would depend on how long the sparrow had been falling.