A particle moving with a constant acceleration from A to B in the straight line AB has velocities u at A and B respectively.lf C is the mid-point of AB then the velocity of particle while passing C will be:

Since the particle is having constant acceleration so its magnitude and direction as well remain constant from A to B. But if the velocity of the particle is same at A and B as well, then the acceleration can not be non zero in magnitude. The situation shown in the question is possible only when the acceleration is zero.

                         V² = U² + 2aS.....[1]

taking the reference if equation [1], we can see a=0 to satisfy the condition in problem.