Answer:
the average speed of the airplane is 560 miles per hour.
Step-by-step explanation:
To calculate the average speed of an airplane, you need to divide the total distance it travels by the total time it takes to travel that distance.
In this case, the total distance is 1400 miles and the total time is 2 and a half hours, so we can calculate the average speed as follows:
Average Speed = Total Distance / Total Time
Average Speed = 1400 miles / 2.5 hours
Average Speed = 560 miles per hour