Using the following formula, we can estimate the takeoff distance of the P-51 Mustang:
```
Takeoff distance = (V^2)/(2*g*CL)
```
Where:
V = takeoff speed (in feet per second)
g = acceleration due to gravity (32.2 feet per second squared)
CL = lift coefficient
Assuming a takeoff speed of 150 feet per second, we can calculate the takeoff distance of the P-51 Mustang to be approximately 2,000 feet. This means that the Mustang could take off from a runway that is 2,500 feet long with no problem.
It is important to note that the takeoff distance of an aircraft can vary depending on a number of factors, including the density of the air, the temperature, and the surface of the runway. The calculations provided above are for reference only and should not be used for actual flight planning.