Final answer:
Betty's elevation at time t while ziplining can be calculated by subtracting the elevation drop, which is 4t meters, from her initial elevation of 1900 meters. Hence, her elevation at time t is 1900 - 4t meters.
Step-by-step explanation:
To solve for Betty's elevation at time t while ziplining, we must use the given ratios and her initial elevation. Betty drops 8 meters in elevation for every 40 meters she travels horizontally. If she travels at 20 meters per second, we can find out how far she travels horizontally at any time t and then calculate the corresponding change in elevation.
The horizontal distance traveled at time t is given by the equation distance = speed × time, or d = 20 meters/second × t. For every 40 meters of horizontal travel, the elevation drops by 8 meters, so the drop in elevation at time t is (d/40) × 8. Substituting d with 20t gives us the elevation drop of t: (20t/40) × 8 = 4t.
To find Betty's elevation at time t, we subtract the elevation drop from her initial elevation of 1900 meters: Elevation at time t = initial elevation - elevation drop = 1900 - 4t.