It is proved that: (1) if the difference of displacement of an object moving uniformly in a straight line is a fixed value in any two continuous equal time, and the acceleration is a, the continuous equal time is t, and the difference of displacement is △ x, then △ x = at2. (2) in the uniformly variable linear motion, the instantaneous velocity at the midpoint of displacement is VX2 = V20 + v2t2

It is proved that: (1) if the difference of displacement of an object moving uniformly in a straight line is a fixed value in any two continuous equal time, and the acceleration is a, the continuous equal time is t, and the difference of displacement is △ x, then △ x = at2. (2) in the uniformly variable linear motion, the instantaneous velocity at the midpoint of displacement is VX2 = V20 + v2t2

① It is proved that: as shown in the figure, if the velocity of the object moving to point a is VA, the acceleration is a, and the adjacent time interval is t, then the displacement time relation is: X1 = VT + 12at2 & nbsp; ① x2 = VBT + 12at2 & nbsp; ② because VB = VA + at & nbsp; ③ substituting ② into ①, X2 = (VA + at) t + 12at2 & nbsp; ③ It is proved by the formula: x2-x1 = △ x = at2. It is shown that if an object moves in a straight line with uniform speed change as shown in the figure, the formula of displacement velocity in the first displacement is: 2aX  v2x2-v02 & nbsp; & nbsp;; and the formula of displacement velocity in the second displacement is: 2aX = vt2-v2x2 & nbsp; & nbsp;; and the formula of displacement velocity in the first displacement is: VX2 = V20 + v2t2