Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Novel Friction Law for the Static Friction Force based on Local
  Precursor Slipping   The sliding of a solid object on a solid substrate requires a shear force
that is larger than the maximum static friction force. It is commonly believed
that the maximum static friction force is proportional to the loading force and
does not depend on the apparent contact area. The ratio of the maximum static
friction force to the loading force is called the static friction coefficient
mM, which is considered to be a constant. Here, we conduct experiments
demonstrating that the static friction force of a slider on a substrate follows
a novel friction law under certain conditions. The magnitude of mM decreases as
the loading force increases or as the apparent contact area decreases. This
behavior is caused by the slip of local precursors before the onset of bulk
sliding and is consistent with recent theory. The results of this study will
develop novel methods for static friction control.

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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc