Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mass redistribution in variable mass systems   We have developed an alternative formulation based on ${\bf F} = M {\bf a}$
rather than ${\bf F} = d{\bf P}/dt$ for studying variable mass systems. It is
shown that ${\bf F} = M {\bf a}$ can be particularly useful in this context, as
illustrated by various examples involving chains and ropes. The method implies
the division of the whole system into two parts, which are considered
separately, allowing to explore certain aspects as constraint forces.

37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
9
The categories of this paper are: nlin