Stroboscopic photography is a common experimental means to study variable speed motion.

1 In any two shooting periods, the falling distance of the ball meets the following requirements: 1: 3: 5: 7. ...

2. The motion of free falling body is uniformly accelerated.

Method for calculating acceleration:

1 Use h =1/2 * g * t 2 (square of t) for direct settlement.

2 Calculate the moving distance at multiple times, and then use the formula in 1 to reduce the error.

3 Find the speed at two different time points, and then divide the difference by the time difference to get the speed, such as [(28.4-19.6)/0.04-(19.6-12.5)/0.04]100/0.