This is a
plot of vertical acceleration against time
with acceleration in an upwards direction as
positive. Like the Height against Time quick
graph, it was produced using a 4 x 6 font,
running the water rocket simulator in a DOS
box.
Again, as the mouse moves over the plot
area, the values for its position on each
axis are printed on the graph next to each
axis using the appropriate units.
Like the height and velocity graphs, the
different stages of the rocket's flight are
in different colours. With a launch rod, the yellow
portion of the flight gives the rocket its
highest acceleration (it has a large area
whereas the opening in a t-nozzle is only
small) although only for a short time. After
that, the blue
portion - representing the water thrust part
- provides a sustained velocity for a longer
time but at a lower acceleration. The cyan
part of the flight, representing the air part
of the thrust, shows an initial increase in
acceleration although this dies away as the
pressure drops inside the water rocket and
the effects of gravity and drag slow the
rocket down to apogee during the coasting
period (red).
Once the rocket has reached its apogee, the
velocity becomes negative and the parachute
starts its deployment (magenta)
with an increase as the parachute opens to
full size, providing an increase in vertical
acceleration. Once fully open, the velocity
remains constant and therefore the
acceleration remains zero for the rest of
the flight (green)
until it hits the ground.
The other quick graphs (including the
statistics) can be accessed by pressing the
initial letter for each page.