1
CIRCUITS
     In this program, you can build electrical circuits using
batteries, switches, and lights.  By flipping switches and burning out
light bulbs, you can see how the circuit you build works.

     In the program, the initial display shows the last saved circuit
and gives you four choices:  Simulate Circuit, Edit Circuit, Clear
Circuit (erases all circuit elements), or Return to Main Menu.  In
'Edit Circuit,' you can add/delete batteries, switches, lights,and
wires.  Use the cursor keys to make your selections.

     In 'Simulate Circuit,' circuit voltages are printed and current
flows shown.  Use the cursor keys to cause switches and light bulbs to
change their current state and see the resulting differences in
circuit values.
end
2
LEVERS
     With this program, you can study the three basic lever types and
the balancing (lifting) forces required.  If you choose "Learn About
Levers," you will be taken through several screens of information
defining basic terminology (fulcrum, effort, load), the idea of
mechanical advantage, what effort is required to balance a known load,
and examples of the three types of levers (1st, 2nd, 3rd class).  You
press any key to move from screen to screen.

     If you choose "Work With Levers," the last saved lever
configuration will be displayed, the current values for lever type,
effort, load, and distances will be printed, and the options menu
given.  You have six options:  Change Effort, Change Load, Move
Effort, Move Load, Move Fulcrum, or Return to Menu.  Use the cursor
keys to make all changes.  Once an effort is applied, you will see the
lever move if that effort is sufficiently large.
end
3
MOON LANDER
     You are the pilot of a lunar landing vehicle hovering over the
moon.  You must land it safely using your thrusters.  Once you choose
one of the pilot options, the simulation screen is drawn and the
simulation begins.

     The idea under each option is the same.  Your vehicle is some
height above the surface of the moon at zero speed.  Due to gravity,
you begin to accelerate toward the surface with a corresponding change
(goes negative) in your speed (a negative speed indicates descent -
positive speed indicates ascent).  The current height and speed are
always displayed.  You slow your descent using the two available
thrusters - the thrusters counteract gravity effects.  The left
thruster is turned on/off with the left arrow key and the right
thruster is controlled with the right arrow key.  The idea of the
program is to be going at a slow descent speed by the time your
altitude (height above the moon surface) reaches zero.  The thrust
level may also be controlled (a range from 0 to 10).  The up arrow key
increases the available thrust, the down arrow key decreases this
value.
end
4
WATER WHEEL
     The water wheel examined here is a famous chaotic system known as
Lorenz Water Wheel.  The wheel consists of a long stick that rotates
in a vertical plane about its center.  On the end of each stick are
cans that can be filled with water.  The weight of these cans cause
the rotation of the stick.  The filling source is at the top of the
wheel, so as the cans pass under the source they are filled with
water.  Each can has a hole in it, so the water is constantly draining
and refills are needed to maintain some rotation.  So, in principle,
the wheel works this way:  a can is filled which causes some rotation.
As it rotates, water is lost necessitating refill.  As long as water
remains in either or both cans, there is some motion.  The kind of
motion imparted to the water wheel is where the chaos comes in.

     During the simulation, you only control one parameter - the value
of the input flow source.  This is increased by using the up arrow or
decreased using the down arrow key.  Several displays record the wheel
motion (speed, can height, and can level).
end













