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Name: Riad S.
Status: other
Age: 20s
Location: N/A
Country: N/A
Date: 2001-2002


Question:
My coworkers and I are disputing the trajectory of a bullet. If I was to shoot a bullet with the gun barrel horizontal, when the bullet comes to rest, will it land directly in line with the barrel or would it be slightly to the left or slightly to the right of the barrel? To make sure there is no confusion, we are assuming there is no wind at all. From my knowledge, the bullet rotates clockwise out of the barrel and my assumption is that it will land to the left.


Replies:
The rotation of the bullet has no effect on its trajectory if the axis of rotation is along the path of the bullet. Otherwise, as in pitching a baseball: if the bullet is rotating counterclockwise as seen from above, it will deviate to the right and vice versa, as explained by Bernoulli's equation.

This is true in an inertial system (where Newton's first law is valid). On the earth, which is rotating, strange things happen. If the gun is fired to the north, the bullet will deviate to the right. This can be understood by considering that the earth is travelling to the east at a slower speed the further north one goes (in the northern hemisphere). This also explains why storm systems rotate clockwise (as seen from above) in the northern hemisphere and counterclockwise in the southern hemisphere.

If this is not clear or you would like further words, please let me know.

Best, Dick Plano



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