Final answer:
The constant term 125 in the function represents the initial height of the stone of 125 meters above ground level at the moment it is thrown when the horizontal distance is zero.
Step-by-step explanation:
The constant term 125 in the function h(x) = 125 - 12.75x - 4.5x² is the initial height of the stone above ground level when it is first thrown. This constant term can also be referred to as the y-intercept in the context of the graph of this function. In physics, the y-intercept of a distance vs. time graph typically represents the initial position of an object before it starts moving.
The presence of the constant term 125 indicates that at the moment of launch, i.e., when the horizontal distance x is 0, the vertical height h of the stone is already 125 meters above ground level, suggesting it may have been thrown from a tall building or perhaps a cliff. The positive value indicates that the stone is above ground level. As x increases, the height decreases due to the negative coefficient of the x² term in the function.