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Software of the Month Club 1996 August
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Software of the Month Club 1996 August.iso
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pendulum
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manual22.txt
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1992-03-04
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***** U S E R M A N U A L *****
P E N D U L U M
IBM PC Version 1.0
(a shareware program)
by P.Thieberger
15 Seeley St.
Brookhaven, NY 11719
"Peter Thieberger a member of the Association of Shareware
Professionals (ASP). ASP wants to make sure that the shareware
principle works for you. If you are unable to resolve a
shareware-related problem with an ASP member by contacting the member
directly, ASP may be able to help. The ASP Ombudsman can help you
resolve a dispute or problem with an ASP member, but does not provide
technical support for members' products. Please write to the ASP
Ombudsman at 545 Grover Road, Muskegon, MI 49442 or send a CompuServe
message via CompuServe Mail to ASP Ombudsman 70007,3536."
************************************************************************
Note:
This is an abbreviated manual. When you order your registered copy of
the program, you will receive a printed manual containing much additional
information, an easy derivation of the pendulum formula, a section on
computer simulations, and an Instructor's Guide.
The Instructor's Guide contains sections on the following subjects:
1) Teaching with PENDULUM.
2) HELP SCREENS: Possible modifications or creation of new ones.
3) Additional problems, questions and assignments.
4) A lesson on computer simulations.
************************************************************************
INTRODUCTION
The pendulum is one of the simplest, best known, and most used
mechanical devices. Understanding in detail how it works and why it
behaves the way it does will be an important step in your understanding
of more complicated systems. In learning about the pendulum you will
also start to appreciate the need for more advanced mathematical tools
to describe such systems.
With this program you will be able to create and modify computer
simulated pendulums, you will move their suspension points and see how
they react. You will measure the length and the oscillation periods and
compare your results with calculations. You will actually perform
computer "experiments" but it is very important that you also perform
experiments with real pendulums to acquire a good feeling for mechanical
systems and for experimental methods. Airline pilots use computer based
flight simulators for part of their training but surely you wouldn't
like to find out that they don't do anything else !
One thing computer simulations allow you to do is to create conditions
which you couldn't easily achieve in reality. For instance, this program
allows you to change the gravitational acceleration g and therefore you
can see what a pendulum would do on the moon without the need for space
travel. You can even find out what would happen if g could become
negative! Other aspects which are not so easy to study with a real
pendulum are the behavior for very large oscillation amplitudes or for
cases when the friction is very large or very small etc. These "extreme"
conditions are not only fun to observe, but they often give you a better
understanding of what is going on under more "normal" circumstances.
Other computer based simulations such as the above mentioned flight
simulators are also used to create extreme conditions which one
couldn't, or wouldn't want to create in reality.
There is a section of this program showing a moving pendulum with
attached force and acceleration vectors which is a big improvement over
the static diagrams you find in books. You will also see a dynamic
graphical representation of position, velocity and acceleration plotted
as functions of time and you can stop the action at any instant and read
all the values. Carefully examine these moving diagrams and graphs to
gain a better understanding of how and why the pendulum moves as it
does.
Finally, the program contains problem generators and assignments in
which all the numerical values are changed for each run. You will solve
interesting problems requiring measurements and calculations and you
will see examples of how pendulums can be put to good use. You will
enter your answers and the computer will tell you whether they are right
or wrong.
- 1 -
HOW TO GET STARTED
I will first show you the easiest and fastest way to run the program
directly from the floppy disk. If you also have a hard disk you may
later want to use it instead. In Appendix A you can find instructions on
a couple of different ways to copy the necessary files to the hard disk.
It is in general a good idea to make a back-up copy of your floppy disk
especially if you plan to run the program repeatedly from that disk.
Please see Appendix B for instructions on how to make copies of this
program for back-up purposes of for distribution to other users. This is
a shareware software product, and we rely on users to order their own,
registered, copies should they find the program interesting and useful.
Now do the following:
1) Insert the floppy disk in the floppy disk drive which we will
assume is drive "A" and close the door or lever. (If the floppy
disk drive you are using is "B" instead, then change all the "A"s
to "B"s in these instructions.)
2) If there is any program running on your computer, terminate it by
using the command(s) appropriate for exiting or ending that
program.
3) If the computer has more than one disk drive, type a: followed by
pressing the "ENTER" key. In what follows we will symbolize the
pressing of "ENTER" by the symbol <- ; so we will simply say: type
a:<- . If you don't know whether there is more than one drive type
a:<- anyway to ensure that A be the active drive.
4) Now type PENDULUM <- and, if you have a registered copy, the
program will start in a few seconds with a nice display on the
screen. This display will disappear by itself and you will see the
main menu. If you want to reach the main menu sooner, all you have
to do is to press any key and the menu will appear almost
immediately.
If your copy of the program is not registered, you will first see
a couple of screens telling you the number of times you have run
the program, asking you to get your own registered copy, offering
ordering information and encouraging you to make as many copies as
you like for your friends.
- 2 -
HOW TO "NAVIGATE" THROUGH THE PROGRAM
This program, like most other computer programs consists of several
different sections and you will see different screen displays in
accordance to which section is active at the time. The MENU is the
origin for selecting the various available sections. This is where
the program starts and you can always go back to the MENU to make another
selection. The MENU screen display looks as follows for this program:
*****************************************************************
<<<<<< P E N D U L U M >>>>>>
Copy registered to John Doe
╔═════════════════════════════════════════╗
║ * E X P E R I M E N T * ║
║ * A N A L Y S I S * ║
║ * P R O B L E M S L E V E L 1 * ║
║ * P R O B L E M S L E V E L 2 * ║
║ * P R A C T I C E * ║
║ * L O S T I N S P A C E * ║
║ * S H O R T R U N W A Y * ║
║ * M O O N E S C A P E * ║
║ * Q U I T * ║
╚═════════════════════════════════════════╝
To select, use the arrow keys and then press
<ENTER> or press one of the highlighted characters
Figure 2.
*****************************************************************
The labels you see inside of the rectangle in Fig. 2 are the different
available options. To select one of them you can use one of two methods:
a) Use the up or down arrow keys to position the horizontal bar
on the item you want, and then press the <ENTER> key.
or
b) Press the key indicated by the emphasized letter contained
in each of the labels.
At the bottom of each of the screens selected from the main menu you
will find abbreviated instructions to remind you of which keys to use.
Those abbreviated instructions which are not totally self explanatory
are described below for the different sections:
- 3 -
a) EXPERIMENT Section
INSTRUCTION MEANING
F3,4:L=0.9m Use the function key F3 to decrement, and F4 to
increment the length L of the pendulum. As long as you
keep one of these keys depressed the value of L will
continue changing until a maximum or minimum value is
reached.The value of L is 0.9 meters in this
example.
F5,6:g=9.8m/s^2 Use the function key F5 to decrement, and F6 to
increment the gravitational acceleration g. The value
of g is 9.8 meters per second squared.
F7,8:friction=10 Use the function key F7 to decrement, and F8 to
increment the friction at the suspension point of the
pendulum. The present value of the friction, in
arbitrary units, is 10.
F9:timer Pressing the F9 function key will start the timer and
you will see the word TIMING displayed at the top
right corner of the screen. Pressing F9 again will
stop the timer and you will see the elapsed time in
seconds at the top right corner. Pressing F9 once more
will reset the timer to 0.0s.
b) ANALYSIS Section
INSTRUCTION MEANING
F2:mass ─┐
│
F3:amp. │ These instructions mean that each of the
│ listed quantities can be switched back and
F4:length │> forth between two preset values by using the
│ corresponding function key (amp. stands for
F5:g │ amplitude and g for gravity). The friction
│ is turned on and off by pressing F6.
F6:friction │
─┘
F7:stop Pressing F7 stops the action and displays the
instantaneous value of several variables in the lower
right part of the screen.
- 4 -
c) PROBLEMS (levels 1 and 2)
INSTRUCTION MEANING
F1:help The upper right section of the screen will show a
list of symbols and their meanings for the variables
used in this problem. Pressing F1 again will restore
the graphic normally seen in that section of the
screen.
F4:hint The upper right section of the screen will show an
equation that can be used for solving the question
being asked. Using a hint will result in a slight
reduction of the final score.
F8:mode Used to toggle between the "normal" mode where
questions are asked in a random order, and "easy"
mode where questions are sequenced so as to provide
the required values for each subsequent step.
d) ASSIGNMENTS
These are the 5th through 8th options of the menu. They are called
PRACTICE, LOST IN SPACE, SHORT RUNWAY, and MOON ESCAPE. In each case a
short description of the assignment is given at the very top of the
screen. The use of the function keys, mentioned at the bottom of the
screens are the following:
INSTRUCTION MEANING
F1:HELP This command will lead to one or more screens
containing detailed descriptions of the
assignments as well as instructions and
suggestions.
F2:enter your
answer A screen will be shown with the questions asked by
this assignment. Make this selection after you have
worked out your answers. You can always come back to
the main screen and repeat the assignment, but each
time you do, the numeric values of the problem will
have changed.
- 5 -
F7,8:friction=10 Use the function key F7 to decrement, and F8 to
increment the friction at the suspension point of
the pendulum. The present value of the friction in
arbitrary units is 10. Use this feature for stopping
the pendulum when you must measure its length, or to
reduce the amplitude before measuring the period.
F9:timer Pressing the F9 function key will start the timer
and you will see the word TIMING displayed at the
top right corner of the screen. Pressing F9 again
will stop the timer and you will see the elapsed
time in seconds at the top right corner. Pressing F9
once more will reset the timer to 0.0s.
RUNNING THE PROGRAM WITH OR WITHOUT A MOUSE
You will be able to move the suspension point of the pendulum in all the
sections of this program except in the "ANALYSIS" and the "PROBLEM"
sections.
If your computer has a "mouse" as a pointing device the program will use
it to let you move the suspension point to any position on the screen
and to initiate the oscillations. It is a real advantage to have a mouse
for running this program because you can actually control the pendulum
with motions of your hand. This gives you a realistic sensation of how
the pendulum reacts.
If your computer doesn't have a mouse the program will automatically
allow you to use the arrow keys to move the pendulum suspension point.
You will get an accelerating motion of the suspension as long as you
press the arrow key, and a sudden stop when you release it. This will
of course cause the pendulum to oscillate when the motion is horizontal.
For easier adjustment of the oscillation amplitude you can also press
the space bar to stimulate the oscillations.
- 6 -
APPENDIX A
HOW TO INSTALL THE PROGRAM ON THE HARD DISK
If your computer has a hard disk you can make a directory for the
PENDULUM program and copy all the files from the floppy disk to that
directory. From then on all you need to do each time you want to run the
program, is to change to that directory and to type PENDULUM <- .
An easier and better procedure for installing the PENDULUM files is by
using the INSTALL program which is on your floppy disk. This procedure
is described in detail below:
1) If there is any program running on your computer, terminate it by
using the command(s) appropriate for exiting or ending that
program.
2) Insert the PENDULUM floppy disk in the floppy disk drive which we
will assume is drive "A" and close the door or lever. (If the
floppy disk drive you are using is "B" instead, then change all the
"A"s to "B"s in these instructions.)
3) Now, type A: followed by pressing the "ENTER" key to ensure that
the appropriate disk is active. (In what follows we will symbolize
the pressing of "ENTER" by the symbol <- ; so we will simply say:
type A:<- ).
4) Now type INSTALL <- and the "INSTALL" program will start by
asking you for a directory name to use on your hard disk. If
you don't answer this question and just press <- , then the
directory C:\PENDULUM will be created and used. If C:\PENDULUM
already exists and contains old files, the program will request
your permission to delete the old files. If you don't want to use
C:\PENDULUM, or if your hard disk is D instead of C, then enter
any other valid directory name such as D:\PEND <- . You can also
use subdirectories. If for instance C:\PHYSICS already exists, you
can enter C:\PHYSICS\PENDULUM <- to store your files in a
subdirectory of PHYSICS called PENDULUM.
5) After a short while, you will see a message on the screen telling
you that the installation is complete, and you will be asked, at
the bottom of the screen, if you want to run the program now. If
you answer y (for yes) the program will be loaded and run from
the hard disk.
6) From now on you will not need the floppy disk and all you need to
do to run the program is to choose the directory where the PENDULUM
files are, and then type PENDULUM <- . For example, if the
directory is C:\PENDULUM , you first type C:<- to ensure that
the C is the active drive, then you type cd \PENDULUM <- to
choose that directory and finally type PENDULUM <- to start the
program.
- 7 -
APPENDIX B
HOW TO GET A REGISTERED COPY AND HOW TO DISTRIBUTE THE PROGRAM
If the copy of PENDULUM you have is not registered, we would like you to
try it and to see if you find it interesting and useful. If you do, I
hope you will use the easy ordering instructions you are offered when
running the program. For a very modest price, you will receive the
latest version of the program and a more extensive printed manual,
containing additional explanations and an INSTRUCTOR'S GUIDE. You will
also be informed about future upgrades and about our new educational
programs. Finally, purchasing the program, you will contribute to
further software developments and to making the "shareware" system work.
You are welcome to make back up copies of PENDULUM for yourself and also
to distribute copies as widely as you like, whether your copy is
registered or not. The copies you distribute for use on other computers
must contain all the files and be identical to the original you
received, or they will not run on other machines. Copies of a
registered version of PENDULUM will automatically become unregistered
when run on a different computer. We will consider two cases for making
copies. The first one is for systems having at least two disk drives and
the second one is for systems having only one.
Case 1: SYSTEMS WITH TWO DISK DRIVES
If you have a hard disk on which you installed the PENDULUM files (see
appendix A), or if you have two floppy disk drives then the easiest way
for making copies is to use the INSTALL program. In either case use the
DOS cd command to change directory to the one containing the PENDULUM
files, and then type INSTALL <- . When asked for the destination
directory type either a:<- or b:<- depending on where you want the
copy to be generated. Whichever drive you choose must of course contain
a blank, and previously formatted floppy disk.
Case 2: SYSTEMS WITH ONLY ONE DISK DRIVE
1) Terminate any program that may be running and then type:
diskcopy a: b:<- .
2) Now follow the instructions which you will see on the screen. When
the computer instructs you to insert the "source" disk it means the
disk from which you are copying; namely in this case the original
PENDULUM disk. When you are instructed to insert the "target" disk
it means an empty disk on which the copy will be written. (This
empty disk does not need to be previously formatted).
3) You may be instructed to swap diskettes several times depending on
the size of the memory. When finished, the computer will prompt you
with the following message:
Copy another diskette (Y/N)?
Type N (for NO) to terminate the procedure or Y (for YES) if you
want to make more copies.
- 8 -
