I got my pet Shih Tzu Shady Lady (she came with the name, don't blame me) in the sixth grade. Ever since then, I routinely play with her. Sometimes this means playing tug of war and other times I throw the ball around for her. Part of the time this means letting the ball have a free fall. When this happens, the ball is only moving vertically so the acceleration is 9.81 m/s^2 and the ball's initial velocity is always zero, as it falls from rest. Other times I throw it horizontally, which means that the horizontal acceleration will be zero and the initial and final horizontal velocity will be the same.