It can be obtained from h = 12gt2: t=2hg.
(2) After the water drops fall, do a flat throwing action.
The horizontal displacement of the second drop of water is: x 1 = v× 2t = 2v2hg.
The horizontal displacement of the third drop of water is: x 1 = v× 3t = 3v2hg.
When the second drop and the third drop are on the same diameter and located on both sides of point O, the distance between them is the largest.
Then: X = X 1+X2 = 5V2Hg.
(3) Every drop of water falls on a straight line, and the radian of rotation of the disk in Δ t time is kπ.
ω=θ△t=kπ△t=kπg2h，k= 1，2…
Answer: (1) The time interval between two adjacent drops of water is 2hg；;
(2) The maximum distance between the dropping points of the second drop and the third drop on the disk surface can be 5v2hg；;
(3) Make every drop of water fall on the disk in a straight line, and the angular velocity of the disk rotation is kπg2h, k = 1, 2 ...