Answer:
<h2>Non-proportional.</h2>
Step-by-step explanation:
In this situation, the elevator started to move 10 seconds after you stepped on, that means, for 10 seconds, the elevator didn't move at any rate, so the slope of the line that describes this interval is zero, horizontal.
After those 10 seconds, the elevator started to move with a rate of 8 feet per seconds.
So, as you can see, there are two different ratios in the same problem, or in the same graph, that means, this situation is represented by a piecewise function, because there are two differente behaviours with different ratios, that makes the situation non-propotional.
If you graph this problem, there would be an horizontal line at the beginning at
and then a proportional line after
, that change makes the situation non-proportional.