Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Pedagogical Model of Static Friction   While dry Coulombic friction is an elementary topic in any standard
introductory course in mechanics, the critical distinction between the kinetic
and static friction forces is something that is both hard to teach and to
learn. In this paper, I describe a geometric model of static friction that may
help introductory students to both understand and apply the Coulomb static
friction approximation.

5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
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The categories of this paper are: cs
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int