Answer to number 8 please

First segment: The airplane is descending slowly, with time and distance at a 3:1 ratio. It is probably approaching the airport

Second segment: The airplane is maintaining its altitude. It is probably waiting for the other planes to clear away

Third segment:The airplane descending rapidly, with time and distance at a 1:2 ratio. It is probably landing

Sorry, my bad.
To find acceleration, we use v2-v1 /t
40mph - 20mph / 10 min
20mph/10min
We can convert this to 20/6 miles per 10 minutes, and cancel out the 10 min to 20/6 miles, which is 10/3 miles

Answermake them get very hot and over time wear them out;