Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Weighing delta(E)=c^2 delta(m) on a relativistic high-sensitivity
  balance. Its mechanical and thermal equilibrium   We consider the sticky collision between two sphere of equal rest mass,
moving with equal but opposite speeds in a horizontal plane. The collision
takes place on the pan of a high sensitivity balance. The conditions of
mechanical and thermal equilibrium are studied showing that heat developed in
the rest frame of the system has a corresponding inertial mass.

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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: hep-th