Answer
Object a starts with initial 0 velocity with a constant acceleration and then moves for sometime with constant velocity and then again moves with constant acceleration.
Object b starts with some negative velocity with a constant acceleration in opposite direction to velocity so the object decelerates up to the time when velocity becomes 0 and then began to accelerate since the direction of velocity and acceleration becomes same. Acceleration is constant all the time.
Work Step by Step
Object a starts with initial 0 velocity with a constant acceleration and then moves for sometime with constant velocity and then again moves with constant acceleration.
Object b starts with some negative velocity with a constant acceleration in opposite direction to velocity so the object decelerates up to the time when velocity becomes 0 and then began to accelerate since the direction of velocity and acceleration becomes same. Acceleration is constant all the time.