Help a HS teacher understand uniform motion?

  • Context: Undergrad 
  • Thread starter Thread starter William Ray
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Discussion Overview

The discussion revolves around the concept of uniform motion, specifically addressing the belief that an object at rest is not considered to be in uniform motion. Participants explore the implications of defining uniform motion and the relationship between velocity and rest, with a focus on clarifying misconceptions and seeking a deeper understanding of these concepts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants argue that constant zero velocity is indeed a constant velocity, and thus an object at rest should be considered in uniform motion.
  • Others highlight that velocity is a relational property, dependent on the observer's frame of reference, suggesting that "not moving" can be perceived differently depending on the context.
  • A participant proposes that the distinction between "no motion" and "constant velocity" may be a semantic issue, questioning whether it is worth debating.
  • Some participants express frustration over the belief that rest is a privileged state, suggesting that this belief lacks mathematical justification.
  • One participant notes that the only difference between constant velocity and accelerated motion is whether the acceleration is zero.
  • There is a suggestion that a theorem or proof could clarify that zero velocity is a specific case of constant velocity, but no such theorem is presented in the discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether an object at rest is in uniform motion. Multiple competing views remain, with some asserting that rest is equivalent to uniform motion and others maintaining that it is a distinct state.

Contextual Notes

The discussion reveals underlying assumptions about the definitions of motion and velocity, as well as the implications of these definitions in different inertial reference frames. There are unresolved questions about the mathematical equivalence of rest and uniform motion.

  • #61
Chestermiller said:
Thanks. I agree. Apparently William Ray and Spinnor don't get the idea that, if you put a thermometer in a bucket of ice water, the temperature you measure will be 0C.

[edited]
I'm not sure where you get the impression that I don't get that idea. I don't believe anyone's disagreeing with you that the surface of the ground will not exceed 0C. I also don't see why you think this is relevant to the question you asked. You are aware that the temperature of the air, (as well as the black-body temperature of the night sky, though it seems we're mostly ignoring radiation here), are significantly below 0C for much of the winter, in many parts of the world?

If you can find anything in what I've said that suggests that there is not an upper limit to the temperature that the sub-snow ground can attain, I'll eat my shorts. Otherwise I believe you're off base here.
 
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  • #62
William Ray said:
[edited]
I'm not sure where you get the impression that I don't get that idea. I don't believe anyone's disagreeing with you that the surface of the ground will not exceed 0C. I also don't see why you think this is relevant to the question you asked. You are aware that the temperature of the air, (as well as the black-body temperature of the night sky, though it seems we're mostly ignoring radiation here), are significantly below 0C for much of the winter, in many parts of the world?

If you can find anything in what I've said that suggests that there is not an upper limit to the temperature that the sub-snow ground can attain, I'll eat my shorts. Otherwise I believe you're off base here.
I'm very sorry. Please forgive me. This is all my misinterpretation of what you were saying.

Chet
 
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  • #63
Chestermiller said:
I'm very sorry. Please forgive me. This is all my misinterpretation of what you were saying.

Chet

Delighted to hear it! I'd hate to think that one or the other of us had gone insane :-)
 
  • #64
lol what of the blanket of snow keeping the ground cold,

Given "mother in laws" reasoning a thicker blanket would maintain the delta in temps better. I'm sure Canadian golf courses have plenty to say about snow blankets.

I would also imagine the average ground temp has a huge influence on this. I think it might be called "frost depth". The ground where I live is probably only frozen a couple of meters down at it's peak...now does the blanket maintain the frost or protect it from going deeper?
 
  • #65
I’m confused. Is the snow blanket at rest, uniform motion, or non-uniform motion? o0)
 

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