You'd need to specify which aircraft you had in mind. There's a wide variety of military aircraft, each with different functions and different performance capabilities.
The fastest plane was the Blackbird and it flew at 2500 mph.
depends on the plane.
600 mph
9000mph
A fast train can be faster than a slow plane. But even a regular plane will be faster than fast train.
Early versions could go 354mph
80
About 40 miles per hour.
1500
They go the speed limit
the army is chasing rabbits
Yes. A plane goes very fast when taking off. For example, A Boeing's takeoff speed is 280 kph.