High School Why are some random physical quantitites given a name?

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The discussion revolves around why certain physical quantities, like force represented by dp/dt, are given names while others, such as dp/ds, are not. The concept of naming is linked to the usefulness of these quantities in calculations and predictions. A suggestion is made to name dp/ds as 'x-force', highlighting its potential for similar applications as force. However, the conversation acknowledges that naming conventions may depend on factors like frequency of use and relationships to other quantities. Ultimately, there is no straightforward answer to what qualifies a quantity as important enough to warrant a name.
Kumar8434
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##\frac{dp}{dt}## is given the name 'force' but ##\frac{dp}{ds}## has no name. I know 'force' is useful for calculations and predicting the future of the system. If 'convenience in calculations' is the reason why some quantities are given names, then I don't see why ##\frac{dp}{ds}## doesn't have a name.
Let's call ##\frac{dp}{ds}## 'x-force' denoted by ##x##. Then if x-force is a function of time ##x(t)##, then,
$$\int_{t_1}^{t_2}x(t)dt=m(\ln(v_2)-\ln(v_1))$$
which looks similar to the work-energy equation:
$$\int_{s_1}^{s_2}F(s)ds=\frac{1}{2}m(v_2^2-v_1^2)$$
So, x-force can also be used for calculations but is not given a name. Then, what is the basis for calling a physical quantity important and giving it a name?
 
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Kumar8434 said:
Let's call dp/ds 'x-force'...
Yeah, call it what you want, and then go on to stuff that actually matters.
 
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A.T. said:
Yeah, call it what you want, and then go on to stuff that actually matters.
If you don't like the name, then maybe use ##force'##. But why doesn't it matter? I've shown that we can also do calculations with it and predict the future of a system.
 
Kumar8434 said:
But why doesn't it matter?
If it matters to you, name it what you want and be happy.
 
There's no simple answer to your question, but I'd bet some factors include how often these quantities are used, their relationship to other quantities, whether they can be derived from other quantities or not, along with other factors. Some quantities have names but are rarely used. For example, the 2nd derivative of acceleration is known as jounce, but you probably won't encounter that term very often.
 
In sci-fi when an author is talking about space travellers or describing the movement of galaxies they will say something like “movement in space only means anything in relation to another object”. Examples of this would be, a space ship moving away from earth at 100 km/s, or 2 galaxies moving towards each other at one light year per century. I think it would make it easier to describe movement in space if we had three axis that we all agree on and we used 0 km/s relative to the speed of...

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