Understanding the Speed of Bullet and Bomb Blasts

  • Context: High School 
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    Bomb Bullet Speed
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Discussion Overview

The discussion focuses on the speed of bullets and bomb blasts, particularly the initial acceleration phase after firing or detonation. Participants explore the dynamics of velocity changes over time and the factors influencing these changes, including air resistance and gravity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that the speed of a bullet or bomb blast starts slow and increases to a maximum, eventually slowing down due to external factors like air resistance and gravity.
  • Another participant argues that a bullet starts from zero velocity, which is inherently slow, and that any noncontinuous change in velocity would require infinite acceleration, implying a rapid increase to maximum speed near the end of the muzzle.
  • A participant questions the implications of having a longer barrel, suggesting that it could lead to the bullet slowing down within the barrel.
  • Further inquiries are made regarding the length of the barrel and the amount of fuel or propellant used, indicating a need for more specific parameters in the discussion.
  • One participant expresses that they do not have confusion but seek validation of their understanding before exploring related topics.

Areas of Agreement / Disagreement

Participants exhibit differing views on the initial speed of bullets and the effects of barrel length and propellant. The discussion remains unresolved, with multiple competing perspectives on the dynamics of bullet acceleration and the definitions of speed terms.

Contextual Notes

The discussion includes subjective terms like "slow," "at first," and "eventually," which may lead to ambiguity. The implications of barrel length and propellant quantity on bullet speed are also not fully explored.

brbrown
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Could someone please clarify if my understanding of the following is correct or not?
When a bullet is fired from a gun or a bomb explodes, I thought I had read somewhere that, in the first few microseconds, the speed of the bullet or bomb blast is slow at first then increases to a maximum, eventually slowing down if nothing other than air resistance or gravity impedes its progress.
 
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What is the confusion? It's pretty easy to see with the bullet that it starts from zero velocity. That's pretty slow. Any noncontinuous change in velocity would require an infinite acceleration. It follows that it must start "slow" and increase to a maximum. This maximum is very near the end of the muzzle, which means a very short distance and a very short time.

When you use subjective terms like "slow," "at first," and "eventually" it's easy to become confused, because they don't really define anything.
 
If you had a very long barrel it would start slowing down in the barrel.
 
How long? How much fuel / propellant?
 
S_Happens said:
What is the confusion? It's pretty easy to see with the bullet that it starts from zero velocity. That's pretty slow. Any noncontinuous change in velocity would require an infinite acceleration. It follows that it must start "slow" and increase to a maximum. This maximum is very near the end of the muzzle, which means a very short distance and a very short time.

When you use subjective terms like "slow," "at first," and "eventually" it's easy to become confused, because they don't really define anything.

Hello S Happens. Thanks for the reply. I don't really have any confusion. I just wanted to make sure I was right before I pursue another related matter. Thanks for the help.
Hello Atomic Joe and Sophiecentaur, I can see those points would have an effect but not needed for my purpose. Thank you both. Brian
 

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