Stroboscopic photography is the study of variable speed motion.

(1) As can be seen from the figure, the distance of the ball at the same time is getting bigger and bigger, and the distance at the same time is not equal, so the ball moves in a variable speed straight line;

Because s=28.4cm=0.284m t=0.24s, V = ST = 0.284m0.24s ≈1.18m/s. 。

(2) As can be seen from the figure, the relationship between the ball movement time and the corresponding distance is: t 1 =0.04s, s 1 =0.8cm, t 2 =0.08s, s 1 =3.2cm, t 3 = 0.1. S 4 = 12.5cm, t 5 =0.20s, s 5 = 19.6cm, t 6 =0.24s, s 6 =28.4cm The falling distance of the ball is proportional to the square of the corresponding time t, and S2 = 5m/S2. Therefore, we can know that the distance the ball falls from rest is

So the answer is: (1) variable speed linear motion; 1. 18; (2) The distance the ball falls from rest is proportional to the square of time.