A calculator I found on the net says that, at 2,000 fps, it would take 125 ft. of 35 mm. film (1 second) to get 2,000 frames.
16 mm. would run 2.5 sec. with the same numbers.
By way of comparison, the same 125 ft. of film at 24 fps would last 1 min. 23.33 sec. for 35 mm. and 3 min. 28.33 sec. for 16 mm.

Mike