- #1
RodB
- 15
- 0
I have a Q re angular momentum (L) that's causing some heated discussion. A bullet is fired off center toward a rotatable target with an axis from, say, 100m (like a ballistic pendulum). The bullet has a fixed linear momentum and an L that remains constant as it travels toward the target -- Pxr stays constant as R and the angle change in sync.
Now say the shooter's aim is off and the bullet will miss the target a bit. In this case the bullet has the same constant numerical value of linear momentum (with a small change in the vector due to the aim) and a similarly constant L, but this L is numerically different from the first. This means that the bullet can have an angular momentum with a different target separated by distance and angle from the first target (but all in the same fixed unmoving coordinate system), and that this L is different numerically from the first.
The same bullet now has TWO different numerical angular momenta simultaneously. It then follows that the bullet has a simultaneous momenta with MANY (theoretically infinite) "targets". The angular momentum, in this scenario, is not a specific, single, explicit, inherent quality like linear momentum, but rather it is multiple, with each relative to some other object (axis) within the frame. Does anyone agree or disagree? (A rotating body's L is different and seems specific and inherent, but that's not the debate.)
Now say the shooter's aim is off and the bullet will miss the target a bit. In this case the bullet has the same constant numerical value of linear momentum (with a small change in the vector due to the aim) and a similarly constant L, but this L is numerically different from the first. This means that the bullet can have an angular momentum with a different target separated by distance and angle from the first target (but all in the same fixed unmoving coordinate system), and that this L is different numerically from the first.
The same bullet now has TWO different numerical angular momenta simultaneously. It then follows that the bullet has a simultaneous momenta with MANY (theoretically infinite) "targets". The angular momentum, in this scenario, is not a specific, single, explicit, inherent quality like linear momentum, but rather it is multiple, with each relative to some other object (axis) within the frame. Does anyone agree or disagree? (A rotating body's L is different and seems specific and inherent, but that's not the debate.)