All this trouble for one little Geococcyx californianus
Wile E. Coyote
Bleached Bones, AZ 59055
February 6, 2009
Math 236 Students
Norton, MA 02766
Dear Multivariable Calculus Students:
The pain, the agony, the frustration have finally gotten to be too
much. That @!*^@#! Roadrunner is really starting to get
on my nerves.
After all these years of trying and failing with mail-order solutions,
I was able to snag some TARP funds last fall and hired an outside consultant,
ACME Surveying and Parametrization Services, Ltd (ACME SPS), to help me devise a
plan to catch the Roadrunner. Unfortunately, ACME SPS used my payments to help
pay for their advertising campaign during the Super Bowl before they had completed my task.
With the additional oversight requirements pending in the new administration, it seems unlikely
that I will be able to tap the funds again. When I went looking for help in my endeavors,
your enterprising and resourceful
professor naturally referred me to you.
The basic plan is that I will capture the annoying bird by carefully hiding behind a
rather sizable boulder on the side of a hill and launching an aerodynamically designed,
teflon-coated, exploding-net pod (using the ACME
Exploding-Net Pod Launcher, of course) set on a timer that will open immediately over the
Roadrunner and drop the net onto the BEEP-BEEPING fowl as it comes speeding down the
hill on the road at 50 m/s. Here's the basic idea:
This is where I need your help: I've already
picked out the perfect place to hide and the ideal location to capture the Roadrunner,
but I don't know the direction I should aim the launcher
or the speed I should fire it. Your enterprising and resourceful professor suggested that perhaps a little more background is in order.
The crack consultants at ACME SPS have told me that the hill can be modeled fairly closely
by the surface
z=400- x^2/400 - y^2/400
where the positive y-axis points north, the positive x-axis points east,
and the distances are measured in meters. Also, the road that the Roadrunner will be traveling on
corresponds to the graph of
p(u)= ( u, u sin(u/10), 400- u^2/400 - (u^2 sin( u/10)^2) / 400 )
My perfect hiding place is a level area that is close to the point (50,30,783/2), and the spot to capture the
dastardly bird is on the road very close to the point (150,97,320). Furthermore, because of the
mismanagement at ACME SPS, I could only afford the ACME Exploding-Net Pod Launcher that launches
the pod at an angle of 45 degrees to the horizontal.
One of the complicating factors in cartoon land that you may not be aware of
is that gravity has not only a vertical
component, but has southerly and westerly components as well. I'm a pretty smart
carnivore, and I think I could adapt my launching technique to this,
except that the horizontal components of gravity keep changing!
You know the way there are tide tables that tell you when high tide
and low tide are?
Well, here we have gravity tables that tell us what the horizontal
components of gravity will be on specific days.
There is some consistency in that gravity is always pulling
down at 9.8 m/s2, and the southerly and westerly components
vary between 0, 2, and 4 m/s2.
My plan is to snag the scrawny little twerp on Saturday, February 21, when
gravity will be pulling toward the west
at 2 m/s2 and toward the south at 4 m/s2. What I need to know is the direction I should aim the launcher,
the initial speed I should launch the pod, and how I should set the timer so
that the pod will open just as it reaches the Roadrunner. I also, of course,
need to know when I should
launch the pod. Since I will have the opportunity to set this up ahead of time,
I can place a marker on the side of the road so that I know to launch the pod at the instant the Roadrunner passes
this marker on the way to the capture point.
I've been down this road enough times before (pun intended) to realize
that everything may not go exactly as planned on the 26th. Since the
gravity will not always be the same on other days, I also need the
analysis done for the other possible values of the southerly and westerly
components. That way, I'll
be able to try my attack on another day without having to bother you
In order to give me time to fine tune my instruments of destruction,
I will need your report by February 20. Please don't let me down.
I'm getting really tired of this.
Wile E. Coyote
A Few Comments From Your Enterprising and Resourceful Professor
After reading Wile E. Coyote's sad tale, I have a small suggestion that might help
you get started. You may want to find an equation for the path of the exploding-net
pod in terms of time t, the initial speed s, and the direction of the initial launch theta,
measured as an angle north of east. And don't be afraid to use Maple's solve( ) command.