- #1
MALON
- 13
- 0
My dad gave me this question:
"My most recent bout with physics was in my article on arrow flight. I have a question for you.
I was told many years ago that an object (ball, arrow etc.) shot or thrown, (picture a pitcher or archer) does indeed continue to accelerate (increase in speed) for a short time after the force is removed before the forces acting against it begin its deceleration and drop. Is this correct?
So if this is incorrect then an arrow shot from a bow, immediately begins its deceleration the instant it leaves the string. "
I told him that in general physics, once a force is removed from something in this type of case, it has no reason to continue its velocity increase, so it slows down. I used an archery analogy for him: Picture a full length drawnback bow, which we will call 0. Now picture bow at rest, we will call that 1. I told him that the arrow will start slowing down once the string reaches 1, because the string has no more forward pushing forces acting on it, so it can't continue to increase the velocity of the arrow.
I also did tell him that I think that that maximum point of speed is somewhere around 3/4 and that the arrow will start slowing down after that point. I don't actually know if that's correct, it just seems somehow correct to me. And for all your archery buffs, I am talking about a recurve bow, not a compound. I told that a compound probably has maximum speed much closer to 1.
The only explanation I could give him as to why it may continue to accelerate at all would be a wave effect of compressions and rarefactions, like the way when you throw a water balloon, it jiggles and wiggles in the air, jutting it forward sometimes. Same principle that when you are increasing the velocity the arrow (or any object) the atoms are compressed and upon being released they are then then rarified and then(? ha) cause a SLIGHT increase in velocity for only a moment, and only visible at the sub-atomic level.
Thanks guys!
"My most recent bout with physics was in my article on arrow flight. I have a question for you.
I was told many years ago that an object (ball, arrow etc.) shot or thrown, (picture a pitcher or archer) does indeed continue to accelerate (increase in speed) for a short time after the force is removed before the forces acting against it begin its deceleration and drop. Is this correct?
So if this is incorrect then an arrow shot from a bow, immediately begins its deceleration the instant it leaves the string. "
I told him that in general physics, once a force is removed from something in this type of case, it has no reason to continue its velocity increase, so it slows down. I used an archery analogy for him: Picture a full length drawnback bow, which we will call 0. Now picture bow at rest, we will call that 1. I told him that the arrow will start slowing down once the string reaches 1, because the string has no more forward pushing forces acting on it, so it can't continue to increase the velocity of the arrow.
I also did tell him that I think that that maximum point of speed is somewhere around 3/4 and that the arrow will start slowing down after that point. I don't actually know if that's correct, it just seems somehow correct to me. And for all your archery buffs, I am talking about a recurve bow, not a compound. I told that a compound probably has maximum speed much closer to 1.
The only explanation I could give him as to why it may continue to accelerate at all would be a wave effect of compressions and rarefactions, like the way when you throw a water balloon, it jiggles and wiggles in the air, jutting it forward sometimes. Same principle that when you are increasing the velocity the arrow (or any object) the atoms are compressed and upon being released they are then then rarified and then(? ha) cause a SLIGHT increase in velocity for only a moment, and only visible at the sub-atomic level.
Thanks guys!
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