"Stroboscope photography" is an experimental method commonly used to study the movement of objects.

First of all, this is the category of high-speed photography. I can teach you how to calculate it, and you can do it yourself; but I can't do it.

The calculation method is as follows: two balls move in parallel, one is designated as "A" and the other is designated as "B".

Answer 1: The interval between the first image from the left and the second image from the left of A is 0.02 seconds, and the interval from the first left to the right is the distance. Speed ??= distance/time

The first to left is 0.02 seconds, the second to left is 0.02 seconds, how many intervals are there, 0.02*(number of intervals) = time

B is calculated as above. It’s okay to have time for two small balls, A and B.

Answer 2: First, assume that both are moving at a constant speed. Then the time for ball A to go from the left to the right in the picture is the same as the time for ball B to go from the left to the right. According to the question, we know: One of the balls is moving faster and faster. It is easy to answer by looking at the picture, which ball is getting wider and wider, and which ball is getting faster. Because the distance traveled in the same time increases, it means the speed of movement is increasing.

Answer 3: Speed ??= distance/time. For a ball moving at a constant speed, the distance from the first left to the second left is the distance. Distance/0.02 = speed

The speed of a small ball moving at a constant speed is Got it. The distance from the first left to the second left of the variable-speed ball is known, distance/0.02=speed 1; the distance from the first right to the second right of the ball is known, distance/0.02=speed 2; (speed 1+speed 2)/2=average speed .

Note: The arithmetic mean of speed does not calculate the average speed, but calculates the photography frequency. A method of obtaining results from frequency and phase differences. If someone emphasizes that "average speed is not the arithmetic average of speeds", then they must not understand that the key to "stroboscopic photography" is "the frequency of strobing and photography", not the average speed.