(1) According to Figure B, the diameter of the ball is 2.0cm, and the size of the ball in the photo is exactly the side length of a grid, so the side length of each grid is actually 2cm.
Vertical direction: △h=gT2, where △h=( 10-5)×2= 10cm, and it is obtained by substitution: t = 0.1s.
So: f= 1T= 10Hz.
(2) Horizontal direction: x=v0t, where x=5L=0. 1m and t=T=0. 1s, so v0 =1m/s. 。