1. Find the average velocity:

* The average velocity is the average of the initial and final velocities: (75 m/s + 145 m/s) / 2 = 110 m/s

2. Calculate the distance traveled:

* Distance = average velocity * time

* Distance = 110 m/s * 15 s = 1650 meters

Therefore, the plane flies 1650 meters in 15 seconds.