The minimum distance for all involved rockets shall be the complex distance for the total installed impulse of the motors in all rockets when how many rockets are launched simultaneously?

The correct answer is based on the underlying safety protocols established by rocketry associations to mitigate risks associated with multiple rocket launches. When launching multiple rockets simultaneously, the formula for determining the minimum distance required from the launch area to the spectators and other personnel is directly influenced by the total installed impulse of all motors in use.

In this case, when three or more rockets are launched at the same time, the complex distance becomes relevant for ensuring safety. This distance is necessary because it takes into consideration the combined effects and potentials for accidents, which increase significantly with the number of rockets and the total impulse. Each rocket's motor contributes to the overall ballistic profile of the launch, and the potential hazard zone expands accordingly.

Thus, when three or more rockets are involved, the complexity of the flight paths and the associated risks necessitate a greater minimum distance to protect all participants and spectators adequately. This ensures compliance with safety regulations and enhances the overall safety of the launch event.