Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two falling-chain demonstrations based on Einstein's equivalence
  principle   Simple demonstrations based on the equivalence principle are given of how a
folded chain and a horizontal flat chain fall down when one chain end is fixed
to a rigid support.

19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc