If an object moving in a straight line with constant acceleration and non-zero initial velocity arrives at point a through displacement S1 in time t, and then arrives at point B through displacement S2 in time t, the following judgment is correct () A. The velocity of the object at point a is S1 + s22tb. The acceleration of the object is 2s1t2c. The acceleration of the object is S2 − s1t2d. The velocity of the object at point B is 2s2 − s1t

If an object moving in a straight line with constant acceleration and non-zero initial velocity arrives at point a through displacement S1 in time t, and then arrives at point B through displacement S2 in time t, the following judgment is correct () A. The velocity of the object at point a is S1 + s22tb. The acceleration of the object is 2s1t2c. The acceleration of the object is S2 − s1t2d. The velocity of the object at point B is 2s2 − s1t

A. Because the average velocity in a period of time is equal to the instantaneous velocity at the middle time, then the velocity at point a VA = S1 + s22t. So a is correct. B. according to S2 − S1 = at2, a = S2 − s1t2. So B is wrong, C is correct. D. the velocity of the object at point B VB = VA + at = S1 + s22t + S2 − s1t = 3s2 − s12t. So D is wrong