Ref G A and is headlight?

Question

If I was traveling @ the speed of a bullet & shot it from the front of the plane to the back then the bullet would travel at the speed of a bullet relative to inside the plane, however if I stuck my arm outside the plane & fired backwards then surly the bullet would just fall to the ground as the forward speed of the plane would be equal & opposite to the backward speed of the bullet relative to the Earth?

Answer 1

You have not quite grasped the theory of relativity yet. Doesn't matter if you arm is in the plane or out the plane its still going forward at 500mph relaativly speaking the bullet is doing 0mph so when you fire the gun the bullet travels in opposite direction to that of travel at 2000mph the relative difference between the two is 2500mph.
Now do you get it??

Answer 2

The difference between your question and the original one about the headlight is that your's is simply a question of classical physics as nothing is travelling fast enough for Einstein's theory of relativity to be come relevant.

In your case, yes, if you fired the bullet out of the window, then ignoring wind effects resulting from your slipstream, the bullet will fall straight down. When you fire the bullet backwards inside the plane, you could say that the bullet is standing still, and that it's only the speed of the plane that causes it to hit something.

Answer 3

No, but when they tested the SR-71 as an interceptor, it would "catch" bullets fired from it's own cannon. The bullets would decelerate and the plane would collide with them. Not nice when traveling three times the speed of sound. They still left the barrel at the same relative velocity.

Answer 4

I don't understand the question, but the statement in the explanatory paragraph is correct. If I fly at 500MPH and fire a bullet backward with a muzzle velocity of 500MPH, then an observer stationary with respect to the earth would see the bullet simply falling straight to the ground.