No, a penny will not always hit the ground if it is dropped from any height. The outcome depends on various factors such as air resistance, the initial velocity, and the height from which it is dropped.
In a vacuum, where there is no air resistance, all objects, regardless of their mass or shape, would fall at the same rate and eventually hit the ground. However, in the presence of air, objects experience air resistance, which opposes their motion and can cause them to fall more slowly or even reach a terminal velocity.
A penny is a relatively light and flat object, which means it has a large surface area relative to its mass. As a result, it experiences significant air resistance compared to, for example, a dense object like a solid metal ball of the same weight. This air resistance can cause the penny to fall more slowly and potentially reach a point where the upward force of air resistance equals the downward force of gravity, resulting in a constant velocity. In this case, the penny would no longer accelerate and would not hit the ground.
However, it's important to note that under normal conditions, for typical heights from which a penny is dropped, air resistance is not significant enough to prevent the penny from hitting the ground. The penny will generally overcome air resistance and continue to accelerate until it reaches the ground.