You have a custom gun that shoots bullets at 100mph
Somone fire that gun facing forword, form a truck going 100mph. Your standing on the side of the road when this happends. The bullet would be travleing at 200mph right?
Now it passes agian and the gun is shoot facing the back of the truck goig 100mph, right as it passes you. Would the bullet just fall from the ground then it left the barrel to the road were you standing next to?
Yes.
No. It would fall TO the ground, not FROM the ground. (Engrish is key when asking questions like this.)
Sounds like Einsteins Theory of Relativity.
This goes back to the plane thing, it’s all relative, the gun is independent of the truck.
well, technically, the bullet wouldn’t get up to 200, because of differences in air resistance.
But it would stay still and drop because it’s inertial energy will be exactly opposite and equal to the energy that the exploding powder has.
Going with the flow it wouldn’t quite hit 200MPH, but it would be well above 100.
Going the oppositite direction it would just fall to the ground.
But truth be told if you have a gun that can only shoot a bullet at 100MPH that’s a pretty shitty gun. 
Is the truck a Ford Ranger? My old 98 4.0 was governed to 96mph, so it would be impossible to hit 100.
:lol:
“relative velocity”
the theory of relativity had something to do with gravitation and the bending of light