If I fire a bullet backward from an aircraft going faster than the bullet

When you fire a bullet backward from an aircraft that is traveling at a speed greater than or equal to the speed of the bullet, the outcome can be understood through basic principles of relative motion.

Ideal Scenario

If the aircraft is traveling at the same speed as the bullet but in the opposite direction, the net effect is that the bullet's velocity relative to the ground would be zero. In this ideal scenario, ignoring factors like air resistance and the time it takes for the bullet to accelerate to its full speed, the bullet would essentially fall straight down from the point where it was fired1.

Real-World Considerations

However, in the real world, several factors come into play:

• Air Resistance: This will slow down the bullet and prevent it from falling straight down. Instead, it will be deflected and may not fall directly below the point of firing12.
• Acceleration Time: The bullet takes time to reach its full speed after being fired, so it won't immediately cancel out the aircraft's forward velocity1.
• Spin and Other Factors: The spin of the bullet and other aerodynamic effects can also cause it to deviate from a straight downward path1.

Relative Motion

When the aircraft's speed is greater than the bullet's speed, the bullet will still move backward relative to the aircraft but will have a forward component relative to the ground. This means it will not fall straight down but will instead move backward relative to the ground, albeit at a speed less than the aircraft's speed34.

In summary, firing a bullet backward from an aircraft traveling faster than the bullet results in the bullet falling or moving backward relative to the ground, influenced by various real-world factors such as air resistance and the bullet's acceleration time.