What do the three-second end, three-second end, three-second start and four-second start mean respectively in senior high school physics? How to express it with the number axis?

The third end, the third end, the third beginning and the fourth beginning of senior high school physics;

1, the end of three seconds, is the end of 0 to three seconds.

2. At the end of the third second, it is this moment, and at the end of the third second.

Three, three seconds, it's time, three seconds.

The beginning of the fourth second is an instant, and the end of the third second is infinitely close to the fourth second.

Time is a line segment on the number axis, and time is a point. In everyday language, ending, beginning, time and so on are all moments, how long before, after and so on are all times. What second is it now? What time does it mean? 1 sec.

1, time: refers to a certain moment, represented by a certain point on the time axis, such as "the end of 3s"; And "early 4s"

2. Time: it is the interval between two moments, which is represented by a line segment on the time axis.

Extended data

The expression of time in physics;

Moment can be used as a noun in writing, such as exciting moment. In addition, moment can also be used as an adverb to describe verbs, such as being ready at any time.

Time is represented by a point on the time axis. 1，2，3...； 1，2，3 ...

The distance between two moments is a segment on the time axis. Within 1 sec, 2 seconds, 3 seconds ... within 1 sec, 2 seconds, 3 seconds ... the second 4s…… .................................................................................................................... ...

Baidu encyclopedia-moment

Baidu encyclopedia-number axis