A fully loaded 737 aircraft takes off at 250 {\rm km/h}.
To determine the time it takes for a fully loaded 737 aircraft to take off at a speed of 250 km/h, we can use the equation:
time = distance / speed
However, in this case, we need to know the distance the aircraft travels during takeoff. Unfortunately, this information is not provided in the question.
Takeoff distance can vary greatly depending on several factors, including aircraft weight, runway length, weather conditions, and engine power. Therefore, an accurate answer cannot be determined without the specific takeoff distance.
If you have the takeoff distance, you can plug the values into the equation above to find the time it takes for the aircraft to take off at a speed of 250 km/h. Alternatively, if you have information on the acceleration of the aircraft during takeoff, you can use kinematic equations to calculate the time.