Calculating Momentum in a Sword Swing

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SUMMARY

The discussion centers on calculating the momentum of a sword swing described as having the power equivalent to 1 million sword swings. The participant calculates the weight of a person (70 kg) multiplied by 1 million, resulting in 70,000,000 kg, and questions the impact of momentum in this scenario. The conversation emphasizes the importance of understanding momentum and acceleration in physics to evaluate the feasibility of such an exaggerated sword swing. The participant seeks clarity on how much power would be delivered at the moment of impact, given a distance of 5 feet between the characters.

PREREQUISITES
  • Basic understanding of physics concepts, particularly momentum and force.
  • Knowledge of mass and weight calculations in the context of physical actions.
  • Familiarity with the principles of acceleration and its effects on momentum.
  • Understanding of the context in which fictional scenarios apply real-world physics.
NEXT STEPS
  • Research the physics of momentum, specifically the formula p = mv (momentum = mass x velocity).
  • Explore the concept of force and acceleration in relation to swinging objects.
  • Investigate how fictional scenarios can be analyzed using real-world physics principles.
  • Learn about the effects of mass distribution and body mechanics in physical actions like sword fighting.
USEFUL FOR

This discussion is beneficial for writers, game designers, and enthusiasts of fantasy literature who wish to incorporate realistic physics into their narratives, as well as educators teaching physics concepts through engaging examples.

fake_it_real
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Hi,

I'm discussing an issue on a forum with someone. I get the feeling that I am trying to be rational with this person while he is NOT being rational with me.

This may sound a bit dumb, but it's kind of like a fantasy forum. In the story in question, the main character stops a sword blow which has been described as having the power of 1 million sword swings.

I thought this sounded really stupid cause I know 1 million is a really big number. I'd like to use a bit of physics so show just how dumb the idea really sounds, but I myself am very stupid.

I calculated that an average person with a weight of 70kg x 1 million would weigh 70,000,000kg. However, a sword swing also has momentum, so the weight of the strike would actually be greater than 70 million kg, right?

This is on the assumption that the sword swinger is putting all of his 70kg of weight behind the swing, which may not be accurate in a real life context, but in the context of the story I think it is accurate. The context of this scenario is that all of that power is accumulated into a single blade which is swung at it's target.

What I'd like to know is that if, at a distance of roughly 5ft between the two characters, the attacker starts his swing with the power of 1 million men weighing 70kg, how much power is he likely to have at the time that he actually hits the other person, according to the laws of momentum?

Sorry, but I don't really know at what rate he accelerates or if that is even an issue in this equation.


Anyway, thanks for any input offered.
 
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EDIT: If he weighs 154,323,584 pounds he could just lay on the guy (if he doesn't fall through the Earth's crust). Also, a fat guy swinging a sword is the same as a skinny guy swinging a sword.
 
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