Answer:
A. The height of a jump rope being used over time
Step-by-step explanation:
We have, the height is related periodically to the time.
<em>That is, as the time increases the height increases and decreases in a periodic manner.</em>
So, from the options, we see that,
B. The height of an elevator over time.
If we assume any line parallel to x-axis as the ground, then the elevator's height also have negative values.
Thus, this option is discarded.
C. The height of a commuter airplane over time.
The commuter plane once in the air, flies at a constant speed.
That is, the height graph will be parallel to the x-axis in this case.
So, this option is discarded.
D. The height of a hummingbird at a feeder.
The height of a humming bird varies randomly with respect to time and cannot be represented by a periodic function.
So, this option is also discarded.
But, the movement of jump rope is periodic and can be represented by a periodic function as shown.
Hence, option A is correct.
