Why is linear momentum not conserved or realistic here?

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Discussion Overview

The discussion revolves around the question of whether linear momentum is conserved in a hypothetical scenario involving characters from a science fiction context. Participants explore the implications of an elastic collision and the assumptions regarding forces and motion, particularly in relation to a video clip depicting the interaction between Godzilla and other characters.

Discussion Character

  • Debate/contested
  • Homework-related
  • Exploratory

Main Points Raised

  • One participant outlines assumptions about friction and constant velocity, suggesting that the force Godzilla applies needs to be calculated to demonstrate unrealistic momentum conservation.
  • Another participant questions whether the goal is to show a violation of momentum conservation and suggests estimating total momentum before and after the collision based on mass and speed.
  • A different participant notes that science fiction often disregards conservation laws, indicating that while the sliding motion appears unrealistic, they do not see a clear violation of momentum conservation in this case.
  • There is a reiteration of the homework context, with a request for clarity on whether calculating momentum before and after is sufficient to address the question.

Areas of Agreement / Disagreement

Participants express differing views on the realism of the scenario and whether momentum conservation is violated. There is no consensus on the calculations needed or the implications of the scenario.

Contextual Notes

Participants mention assumptions about friction and the nature of the collision, but these assumptions are not universally agreed upon. The discussion remains focused on the hypothetical scenario without resolving the underlying physics principles.

Who May Find This Useful

Readers interested in the intersection of physics and science fiction, as well as those looking for insights into momentum conservation in non-traditional contexts, may find this discussion relevant.

Gusta257
- This is the situation provided where it has to be demonstrated that linear momentum is not conserved or unrealistic. My assumptions are: there's no friction due to how Godzilla is moving, the sand is acting as a lubricant. Velocity is constant. This is an elastic collision. I also guess that we have to calculate the force that Godzilla applies on the two masses combined (Megalon and Jet Jaguar) in order to prove that the force required for Godzilla to push both Megalon and Jet Jaguar is unrealistic.

My problem is, I don't really know how to calculate the force that Godzilla applies on both masses. And if that's not what's need to calculate, then I really don't have an idea of what to calculate to prove linear momentum is not conserved/unrealistic.
 
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If I understand properly, you want to demonstrate that what happens in the video clip is impossible because it implies a violation of conservation of momentum? Is this a homework/ coursework question?

You should be able to make a reasonable estimate of the total momentum before and after the collision from reasonable estimates of the mass of the participants and their before and after speeds.
 
Science fiction like this rarely cares about conservation of momentum. The authors simply ignore it. In this particular case I don't see an obvious violation of it. The sliding approach looks really unrealistic, however.
 
Nugatory said:
If I understand properly, you want to demonstrate that what happens in the video clip is impossible because it implies a violation of conservation of momentum? Is this a homework/ coursework question?

You should be able to make a reasonable estimate of the total momentum before and after the collision from reasonable estimates of the mass of the participants and their before and after speeds.
Yes to both questions, this is a homework question. So I only need to calculated momentum before and after?
 
Gusta257 said:
Yes to both questions, this is a homework question. So I only need to calculated momentum before and after?
Because it is a homework question, you'll want to post it in the homework forum: https://www.physicsforums.com/forums/introductory-physics-homework.153/
Start a new thread there... and fill out the template properly when you do.

This thread is closed.
 

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