Answer
a) See the figure below.
Work Step by Step
a) As you see in the figure below, it seems that the vertical component of the object's velocity increases while falling down. Thus, the acceleration is always directed down since it is the free-fall acceleration $(a=g)$ and since the horizontal velocity component is constant.
b) A toy car pushed by a kid on a frictionless table, so it moved at a constant velocity of 1 m/s until it reached the edge of the table it falls down toward the ground while continue moving horizontally at a constant speed.