We live in a world that is defined by three spatial dimensions and one
time dimension. Objects move within this domain in two ways.
or changes location, from one
point to another.
And an object
or changes its attitude.
In general, the motion of any object
involves both translation and rotation.
The translations are in direct response to external
The rotations are in direct response to external
torques or moments (twisting forces).
of a rocket
is particularly complex because the rotations and translations
are coupled together; a rotation affects the magnitude
and direction of the forces which affect translations.
To understand and describe the motion of a rocket, we usually try
to break down the complex problem into a series of easier problems.
We can, for instance, assume that the rocket translates from one
point to another as if all the mass of the rocket were collected
into a single point called the
center of gravity.
We can describe the motion of the center of gravity by using
laws of motion. In general, there are four
forces acting on the rocket; the weight,
thrust, drag and lift.
Forces, Torques and Motion:
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