Modeling in Engineering
The descriptions of most scientific problems involve equations that relate
the changes in some key variables to each other. Usually the smaller the
increment chosen in the changing variables, the more general and accurate
the description. In the limiting case of infinitesimal or differential changes
in variables, we obtain differential equations that provide precise mathematical
formulations for the physical principles and laws by representing the
rates of change as derivatives. Therefore, differential equations are used to
investigate a wide variety of problems in sciences and engineering (Fig.
1–35). However, many problems encountered in practice can be solved
without resorting to differential equations and the complications associated
with them.
The study of physical phenomena involves two important steps. In the
first step, all the variables that affect the phenomena are identified, reasonable
assumptions and approximations are made, and the interdependence of
these variables is studied. The relevant physical laws and principles are
invoked, and the problem is formulated mathematically. The equation itself
is very instructive as it shows the degree of dependence of some variables
on others, and the relative importance of various terms. In the second step,
the problem is solved using an appropriate approach, and the results are
interpreted.
Many processes that seem to occur in nature randomly and without any
order are, in fact, being governed by some visible or not-so-visible physical
laws. Whether we notice them or not, these laws are there, governing con
Modeling in Engineering
The descriptions of most scientific problems involve equations that relate
the changes in some key variables to each other. Usually the smaller the
increment chosen in the changing variables, the more general and accurate
the description. In the limiting case of infinitesimal or differential changes
in variables, we obtain differential equations that provide precise mathematical
formulations for the physical principles and laws by representing the
rates of change as derivatives. Therefore, differential equations are used to
investigate a wide variety of problems in sciences and engineering (Fig.
1–35). However, many problems encountered in practice can be solved
without resorting to differential equations and the complications associated
with them.
The study of physical phenomena involves two important steps. In the
first step, all the variables that affect the phenomena are identified, reasonable
assumptions and approximations are made, and the interdependence of
these variables is studied. The relevant physical laws and principles are
invoked, and the problem is formulated mathematically. The equation itself
is very instructive as it shows the degree of dependence of some variables
on others, and the relative importance of various terms. In the second step,
the problem is solved using an appropriate approach, and the results are
interpreted.
Many processes that seem to occur in nature randomly and without any
order are, in fact, being governed by some visible or not-so-visible physical
laws. Whether we notice them or not, these laws are there, governing con
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