Question

Can the velocity of a body reverse the direction when acceleration is constant? If you think so, give an example.

Answer 1

Consider a particle moving to the left with some speed v. If we take leftward to be the negative direction, then the particle's velocity is -v, and it's moving in the negative direction.

Now give the particle a positive acceleration pointing rightward. The particle will eventually slow to a stop before increasing its speed in the positive direction.

So the answer is yes, the direction in which a body is moving can be reversed with constant acceleration.