The initial acceleration is
g but
a
decreases with
t or
y. If we insert equation (3.4) or
(4.1) into equation (3.2), we see that as
t or
y gets
large
af goes to zero and
vf
becomes constant. We will make more of this starting in the
Terminal Velocity section.
An
applet
allows you to plot eqns (1.4), (2.5) and (1.2) to obtain the velocity
and acceleration of bodies falling in a vacuum. Similarly plots of
eqns (3.4), (4.1) and (3.2) allow you to obtain the velocity and
acceleration of bodies falling in a fluid. Furthermore the value of
k/m can be varied to show the effect of this parameter on the velocity
and acceleration. Practice using the
applet to get a feel for the aforementioned equations and the
effect of k/m on the velocity and acceleration.