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Is the act of gaining mass considered a 'motion'?

  1. Mar 20, 2014 #1
    say a guy is eating and gains mass
    does this act of gaining or losing mass considered a motion?

    i know mass has a property called 'inertia' (or is it the other way around where inertia has the property of mass?)
    and inertia is the 'resistance' to motion or change in state of motion

    but i don't think i'm talking about inertia here...

    what sparked this question?...
    its just that fat people tend to stay fat
    and people that stay healthy tend to stay healthy
    what i'm saying is habits, that people tend to continue to do what they've always been doing
    Newton's First Law:

    "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

  2. jcsd
  3. Mar 20, 2014 #2


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    Some people get fat because they don't move, or move enough.

    But, in the end, everybody dies anyway.
  4. Mar 20, 2014 #3
    ... didn't answer questions..
  5. Mar 20, 2014 #4
    Because that question isn't about physics. Look at the title at the top of the page. It says Physics Forums. Questions that are not about physics have a tendency to remain unanswered around here.
  6. Mar 25, 2014 #5
    then what kind of question is this?

    someone rephrase this: is the act of gaining mass considered a 'motion'? into a "physics" question please, because apparently i'm too stupid to be in this forum...
  7. Mar 25, 2014 #6
    You are just trying to push an irrelevant analogy.
    Newton's laws does not apply to people's habits.
    But if you want to consider getting fat as a kind of motion, go ahead. What else is to it?

    By the way, your premises are not really serious.
    "people that stay healthy tend to stay healthy" ?????
  8. Mar 25, 2014 #7


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    In order to gain mass, motion must be involved, otherwise objects with mass wouldn't come together to form a larger, more massive object.

    Your original question is extremely confusing and involves things that don't fall under physics; IE people's eating habits and other behaviors. That is a social sciences/biology issue. There are many, many reasons people become and remain overweight. The only real physics explanation that applies here is that they don't burn more calories than they take in, which is what is required to lose weight.
  9. Mar 25, 2014 #8

    Vanadium 50

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    The relationship between the original question and physics has been explained. Continuing to use a bad analogy is not going to take us anywhere we want to be.
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