Final answer:
The initial velocity of a ball dropped from rest is zero, as it starts from a state of rest without any push before gravity begins to accelerate it downward.
Step-by-step explanation:
The initial velocity of a ball dropped from rest by a person standing on a cliff is zero. Since the ball is being dropped and not thrown, it starts from a state of rest, meaning its initial velocity is 0 meters per second (m/s). If the ball is dropped, meaning the person releases it without giving it any push, the initial velocity is simply the starting velocity, which in this case, is zero because it starts from rest. The velocity will increase in the negative direction (downwards) as the ball accelerates due to gravity when free falling.