moved through during the first second, and let the line B F represent
the velocity of two feet per second, acquired by the body at the end of
it. Now let us imagine the action of the accelerating force suddenly to
cease, and the body to move on merely with the velocity it has acquired.
During the next second it will move through two feet, as represented by
the square B F C I. But in fact, the action of the accelerating force
does not cease. This force continues to be exerted, and produces on the
body during the next second the same effect that it did during the first
second, causing it to move through an additional foot of distance,
represented by the triangle F I G, and to have its velocity accelerated
two additional feet per second, as represented by the line I G. So in
two seconds the body has moved through four feet. We may follow the
operation of this law as far as we choose. The figure shows it during
four seconds, or any other unit, of time, and also for any unit of
distance. Thus:

Time 1 Distance 1
" 2 " 4
" 3 " 9
" 4 " 16

So it is obvious that the distance moved through by a body whose motion
is uniformly accelerated increases as the square of the time.

But, you are asking, what has all this to do with a revolving body? As
soon as your minds can be started from a state of rest, you will
perceive that it has everything to do with a revolving body. The
centripetal force, which acts upon a revolving body to draw it to the
center, is a constant force, and under it the revolving body must move
or be deflected through distances which increase as the squares of the