If the average velocity of the particle moving from the end of 5S to the end of 19S is 3.6m/s, the displacement of the particle in the first 8s can be calculated by the proportional method

If the average velocity of the particle moving from the end of 5S to the end of 19S is 3.6m/s, the displacement of the particle in the first 8s can be calculated by the proportional method

The middle time from 5S to 19S is 12s, and the average velocity from 5S to 19S is the average velocity in this period, which is the instantaneous velocity at the end of 12s. Then the displacement from 0 to 12s is used again: the velocity at the end of 6S is the average velocity from 0 to 12s, V6 = (0 + 3.6) / 2 = 1.8m/s, and the displacement in the first 12s x = V6 × 12 = 21.6