1. Title : Simulation on Pendulum Story
Aim :
1. To apply the simulation software in teaching and learning process
2. To conduct the experiment by using STELLA software
3. To understand the uses of simulation in teaching and learning process
4. To identify which factors influence the period, T, of the pendulum
5. To investigate the relationship between mass, initial displacement and length of string
on the amplitude, period and frequency of a simple pendulum
Introduction :
Simulation is an abstract representation of a real situation in which students can
interact with each other based on their respective roles to solve any problem or issue related.
It is also a situation that was created to resemble the real situation by using the problems
really exist or provide situations that are exist in a controlled environment. Simulation is
a representation of the operation or features of one process or system through the use of
another. It is also one of the imitation as of a potential situation or in experimental testing. In
a simulation, the learner acts, the simulation reacts and the learner learns from this
feedback. Simulation can be used to provide a fertile learning environment for student. The
use of activities by using simulation in education is use widely and become an important tool
in school. One type of simulation is computer simulation. According to de Jong (1991), there
are many approaches and learning through simulation like computerized analysis,
experiment and teaching.
The function of using simulation in teaching and learning process is to provide
students with realistic experience as they have to handle and conduct the simulation on their
own. So, they have their own experience on how to use the simulation software, running the
experiment, manipulate the parameter and to produce the output graph. Apart from that,
simulation also is one of the technique for enhancing learning and increase student’s interest
and awareness in the topic being discussed. As a teacher-to-be, we should improve our
teaching skills rather than using a Power point slide or experimental activity. This is because
the students cannot feel the new learning atmosphere in their class. So, when a teacher use
simulation, they can feel this type of teaching is one of the reformation in learning style and
thus can increase student’s interest on the topic. Besides, simulations will provide
opportunities for students to explore environments that mirror real-world situations or
complex ideas. They can see clearly what will happen to the process or situation involve if
they change the parameter involve rather than just imagine it. Simulations also will provide

2. innovative ways to use technology. Due to our world’s modernization, technology will
become as enabler in teaching and learning process. New computer technologies allow for a
variety of strategies to design learning environment that are realistic, authentic, engaging and
gun.
Computer simulation is one of the software applications which enable a user to run a
model of a system. The users can use these type of simulation by interact with the computer
system, setting the input variables and observe the changes occur for the output. They also
can explore more about the model in a real time by running the simulation which it can be
start and stop the model, make changes to the test hypothesis and conclude what has been
occur. Simulation has its own characteristics such as:
1. Simulation is an experiential learning which it allows participants learn from
their mistakes and have the opportunity to improve themselves in any
situation.
2. In the simulation, participants play quite wide role because the participants are
not only required to maintain a role as determined but they will need to
discuss and contribute an idea to make decisions.
3. Participants are required to interact dynamically in related systems, make
decisions and solve problems.
4. The purpose of the simulation is that it allows students to use the language
with more work and gives students the opportunity to interact and
communicate effectively.
5. One of advantages of this technique is it allows students to discuss and think
creatively and critical analysis.
Learning through computer simulation can be divided into four which are create a
formula, establish teaching goals, specific teaching process and establish learning activities.
Using computer simulations in the learning process has some importance. The main
importance is to make sure students are active in the exploration and can learn something in
which the approach used has connection with the modern learning theory. Computer
simulation learning is more on experiential learning that require support from the instructor or
system to ensure the simulation has been used effectively.
There are some advantages of using simulation especially for computer simulation
like the students can observe, explore, recreate and receive immediate feedback about the
real phenomena or processes occur or in the other word can enhance the student’s
motivation. Besides, simulation can help the students to promote further investigation. After
studying the learning of materials and experiencing the simulation program, some students

3. may want to do further exploration with the learning contents and computer simulation
program makes it possible for them to manipulate and experiment with the phenomenon or
process. They can change the values of input parameters and examine which output
variables are changed consequently and how they are changed. The next advantages of
using simulation in teaching and learning process is simulation provides supportive and
constructivist learning. This is because when students work with a simulation program, they
will play an active role in their learning process and build their own knowledge through active
interaction.
There are many simulation software in market like ACSL, APROS, ARTIFEX, Arena,
AutoMod, C++SIM, CSIM, Call$im, FluidFlow, GPSS, Gepasi, JavSim, MJX, MedModel,
Mesquite, Multiverse, NETWORK, OPNET Modeler, POSES++, Simulat8, Powersim,
QUEST, REAL, SHIFT, SIMPLE++, SIMSCRIPT, SLAM, SMPL, SimBank, SimPlusPlus,
imApp, STELLA, TIERRA, Witness, SIMNON, VISSIM, VenSim and Javasim. So, in this
project we will conduct a model or graphical simulation by using one of the simulation
software called STELLA (Structural Thinking Experimental Learning Laboratory with
Animation).
I will introduce a little bit about STELLA before explain a model that I have choose.
STELLA software has similar dynamic simulation software like SimApp, Simile and VenSim.
STELLA models consist of four basic components such as stock, flow, converter and
connector. Stock is a noun and represents something that accumulates. Some examples of
stocks are population, radioactivity, enzyme concentration, self-esteem and money. Flow is
an activity that changes magnitude of stock, converter is use to convert, stores equation or
constant while connector is use to transmits inputs and information.
In this project, I have decided to conduct a simulation on the pendulum story. In this
simulation, I have to investigate some factors such as mass of bob, length of string and initial
displacement towards the amplitude, period and frequency of the pendulum’s motion.

4. Result and Discussion:
a) Normal graph
The above graph shows the normal graph for the displacement over time for a simple
pendulum motion. As we can see, the graph formed sinusoidal graph and the pendulum
motion will experience simple harmonic motion. Simple harmonic motion is a type of periodic
motion where the restoring force is directly proportional to the displacement. In this
simulation, I have set three variables for this model such as mass of bob, initial displacement
and string length with mass of bob = 1.00 kg, initial displacement = 0.10 m and the string
length = 1.0 m. So, in this model we need to investigate the effect of mass of bob, initial
displacement and string length with the time required to complete one oscillation for example
from one crest to the next crest which is called the pendulum’s period. Pendulum period is
measured in seconds. For a simple harmonic motion, the period is given as
T = 2π √m/k
Substituting k = mg /L into the equation and the formula to calculate this quantity is given as

5. Where L = length of string in meters
G = gravitational field strength or acceleration due to gravity
The quantity for g at sea level is 9.81 m/s2 and can be calculated as
When we already find the period of pendulum, we can also find the frequency of the
pendulum in Hz and is given by
f=1/T
Where T = period of pendulum in second
A simple pendulum consists of a weight suspended on a string or wire. If the pendulum
weight or bob is pulled to a small angle from the vertical and let go, it will swing back and
forth at a regular period and frequency. Although damping effects from air resistance and
friction are a factor but in this simulation they are considered negligible for the basic
equations concerning the frequency of the pendulum. The diagram below shows the
amplitude, frequency and the period of a simple harmonic motion graph for make us
understand more about this type of model.
In teaching and learning process, to make student understand what they want to do is
firstly, we need to understand clearly about the theory or concept for the topic we had chose.
Then, see the parameter involved in the simulation. In this simulation there are three

6. parameters involved which are mass of bob, initial displacement and string length. Then,
click ‘RUN’ to see the shape of the theoretical graph. So, from the graph illustrated above,
the graph formed sinusoidal shape. The graph shows displacement vs. time and this will
refer to the simple harmonic motion of a pendulum. So, the next step is we will change one of
the parameter and see what will happen to the graph.
b) Effect Of Mass
In this part, the length of the string and the initial displacement were kept constant
while varying the mass of the bob. Three trials were conducted with masses of 1.2 kg, 1.4 kg,
1.6 kg and 1.8 kg. As we can see from the diagram shown above, there is no variation for the
graph. It means that as the mass increases, the period of pendulum remains the same or
have a little effect upon the period of the pendulum. Same goes to the amplitude which mass
of bob do not altered the amplitude of the pendulum’s motion. Notice that the mass of the
bob does not appear in the above equation. This means that no matter what the mass were
hang out at the pendulum, it will gives the same value or same variation for the period of

7. pendulum. Same goes to the frequency of the pendulum. Mass of bob will not affect the
frequency as it has no changes in the period. In the other words, a pendulum with a heavy
bob will move at the same rate as one with a lighter bob. On the other hand, the period is
influenced by the position of the pendulum in relation to the earth since the acceleration of
gravity on a falling object is independent of the mass of the object.
For the first parameter, we have changed the mass of bob with another two
parameters which are initial displacement and string length were kept constant. So, before
we start ‘RUN’, we need to move the knob for the mass of bob up to any values you want.
For example, move the knob of mass of bob to 0.2 kg. Then, click ‘RUN’ to see what happen
to the graph. The graph will illustrated as shown. Next, if we want to clear the first graph, we
just need to click ‘RESET’. If we want to compare the graph for all the values of mass of bob,
we just change the next value of mass of bob by moving the knob and click ‘RUN’. So, from
that we can compare the graph for all values we change as well. So, as we can see from the
graph shown above, there was no variation for the mass of bob. Means that, mass of bob did
not alter the values of pendulum period and thus will not become the factor to the period of
pendulum.
c) Effect of Initial Displacement

8. In this part, mass of bob and length of string were kept constant while initial
displacement was varied. I have set the initial displacement with -0.02 m, -0.01 m, 0.01 m
and 0.02 m. From the graph, we can see that the period of the pendulum does not change
but the amplitude of the motion has changes. As the magnitude of the initial displacement
increases, the amplitude of the pendulum’s motion will increases as it travels farther back
and forth. The magnitude of the initial displacement does not gives any effect on the period
or frequency of the pendulum’s motion as the parameter of initial displacement does not
include in the equation to find the period of the pendulum. In this model, I have set the values
of the initial displacement for the negative values and the positive values to compare. So,
from the graph above we can see that for the negative values of the initial displacement
which are -0.02 m and -0.01 m, the graph will starts in the trough of the sine wave rather than
the crest. The positive values of the initial displacement which are 0.01 m and 0.02 m show
that the graph will start in the crest of the sine wave. So, means that in the real experiment
or in the real world, this would indicate whether the bob was initially displaced to the left or
right from the rest position.
Velocity vs. Displacement Graph For The Factors Of Initial Displacement
From the above graph, we can relate the initial displacement with the velocity of the
pendulum. As we can see from the graph, the displacement is zero when velocity is at a
maximum. At this point the pendulum is in the middle or in rest position if in the real

9. experiment. Then, the velocity is zero when displacement is at a maximum. The bob would
be go farther from the middle position either to the right or left as it was going to travel. The
negative values for the displacement and velocity show that the direction of the moving
pendulum as displacement and velocity is vector quantity which is has magnitude and
direction itself.
For the second part, we need varying the initial displacement while another both
parameters were kept constant by not changing them. So, we just alter the values of initial
displacement up to the values we want. Move the knob of initial displacement and click
‘RUN’. Then, see what will happen to the displacement vs. time graph. It still gives the same
shape as it is a simple harmonic motion. Next, move the knob for the second value and click
‘RUN’ again and repeat the same step for the next value for initial displacement parameter.
So, we can see the variation among of these values of initial displacement. From theory, we
already knew that initial displacement has the relationship with the velocity of the pendulum.
So, to see the relationship between them, we can click the ‘dog ear’ at the left side of graph.
Then, it will show the velocity vs. time graph. Thus, we can relate the initial displacement with
the velocity.
d) Effect of Length of The String

10. In the third part, I have varying the length of string while mass of bob and the initial
displacement kept constant. I set the length of string with four different values which are
0.5m, 1.0m, 1.5m and 2.0m. As we can see from the graph above, the sinusoidal wave for
four different values show a big variation compared to the mass of bob and length of string.
For, qualitatively measurement we can see that the increases the length of string, the
increases the period of the pendulum. For quantitatively measurement, we can find the
period of the pendulum by using the formula. So, by using the formula to find the period of
the pendulum, I have calculated the period of the pendulum for each value of the string
length.
Length of String (m) Period of Pendulum (s)
0.5 1.42
1.0 2.00
1.5 2.46
2.0 2.83
From table, we can see that when the length of string increase, the value of the period of
pendulum also become increase. So, the longer the length of string, the higher the period of
the pendulum and thus the frequency become lower. The length of the string does not give
any effect on the amplitude of a pendulum’s motion. So, from the result we can conclude that
only the length of string would gives effect on the period of the pendulum’s motion compared
to mass of bob and the initial displacement. This is because the length of string is one of the
parameter included in the following equation:
When the length is changed, the pendulum will take more or less time to oscillate, depending
on its length and acceleration due to gravity. Therefore, the period may be varied by
changing either of these two factors. Since acceleration due to gravity is constant on Earth,
so the only dependent factor is the length of the pendulum.
The next parameter is length of string. We will keep constant the mass of bob and
initial displacement of pendulum. As stated before, move the knob of string length to the
values we chose. Click ‘RUN’ and observe the graph. As we can see, the graph shows the
variation for all the values and thus the length of string is one of the factor for the period of
pendulum.

11. How Simulation Can Increase Student Motivation And Making Prediction?
Overall, from four graphs above, the simulation can increase student motivation by
increasing the student’s interest. Before they start to conduct the experiment, they will
explore the background of the simulation and the theory of experiment that will conduct.
Then, while perform the simulation they will change the parameter as they can see directly
what will happen to a given phenomena or process illustrated. So, they will feel more
enjoyment in performing an experiment and thus could increase the student’s interest about
that topic.
Besides, during changing the parameter for mass of bob, string length and initial
displacement, there will have variation among four graphs and hence will make the students
to think and work together of a possible solution and prove the answer presented with
certain decision in which among three parameters will affect the period of pendulum’s
motion. In this simulation, the student also will play their role as they require a student’s
involvement and participation. Hence, they will have an experience in conducting an
experiment using simulation.
In this simulation, student will be motivated as they have to follow the step so that
they can conduct the experiment systematically. Firstly, they need to identify the problem
in this simulation sample which is the parameter that influence the period of pendulum’s
motion. Then, after identifying the problem, they have to formulate the problem. Means that,
they have to select the problem to be identified based on the objectives. Then, collect and
run the system. they have to change all the parameters, fix the variables, substituting the
values for variables, observe the output graph and manually checking the result. After that,
the students should validate the simulation by comparing the simulation they have conducted
with the simulation of the real system or theory.
To better understand the motivational impact of using simulation in learning process,
in this experiment, the teacher will ask the students to assume the three parameters which
are mass of bob, initial displacement and string length become the factors that affect the
period of pendulum before running the simulation. With the aid use of computer simulation,
students can find the exact answer for the real answer whether all the parameters become
the factors which affect the period of pendulum or not all. As students click on the parameter
involve on the screen browser, they will get the result and information for each graph display.
Continuing the journey of simulation, at start, they will did not get any problem but when it
comes to the end, for comparing all the graphs, the students encounter a problem and at this
stage, they start to make discussion and reconstruct back their misconception. Such an

12. experience could teach students about the important details about certain concept and allow
students to have a deep exploration.
Besides motivate the students, simulation also allows the students to make
prediction. For example, when they have read and understand the theory of the experiment,
they will get to know what they have to do in the simulation. So, when they have
identified the parameters involve such as mass of bob, string length and initial displacement,
they can predict directly or make an inference what will happen if they change mass of bob,
string length and initial displacement with the period of the pendulum’s motion before running
the simulation. If there is any misconception, it will be explain after analysing the result obtain
from what they have predict. So, in this case, simulation also can construct the abstract
thinking of students.
In making prediction, the use of simulations are use ‘Mental Experiments’ that can
be designed for a wide variety of situations and to make predictions based on numerical
models. For example in our experiment, when the normal graph is running, students will start
to think and imagine using their ‘’mental’’ part to describe about the graph illustrated and
relate it with the principle or any theory. During this stage, students can make prediction by
supporting their imagination with sensory input from a Physical Model of the experimental
system. For example, students can discover a theory or model to explain the motion of the
pendulum by imagine it with the swinging of the cradle which it moves up and down like
simple harmonic motion. So, students can easily capture the concept of simple harmonic
motion which involves amplitude, period and frequency.
In simulation, students will have more into discussion about their coloring
prediction of results. These suggested by the act of more discussion about the result, and
manipulating the computer simulator model will help students make progress towards
developing useful model. During the first trial, students model were not formulated or
detailed, there will have a little discussion about the results. The situation will reverse after
they have tried for many trials and got the last result. The simulator experiment however
because enabled students to focus on model that was visualize and manipulative, generated
extensive discussion when students make predictions and interpreted results.

13. Conclusion
By using STELLA simulation software, the students can create models and run
simulations of systems over time. The results of simulations are displayed with visual
representations to support diverse learning styles. Other than that, by using simulation the
students can understand more and can practice the lesson they have learnt in a classroom
instead of only read the books. They can get to know what will happen to a given system if
change one of the parameter that influence the system of model. So, they can conclude and
summarize the result from the play simulation they have run. From my opinion, I think
simulation is one of the best teaching style in enhancing the student’s achievement for ten
years onward as our world will more developing with the use of technology. Simulation also
will give an opportunity for students to be more active as they have to participate in active
learning. They are called upon to make decisions and through this team-based exercise they
gain a better understanding of process. Ultimately, for me simulation allow for deeper
exploration of a complex issue or concept with greater student involvement and enjoyment in
the learning experience. So, I would strongly suggest and encourage teachers especially for
Science teachers to run the experiment with simulations in their class for authentic,
collaborative and constructivist learning. In response to the challenges experience by
teachers in developing technology, I would advocate two strategies and solutions. First,
make it simple to elaborate the concept and the second, continue to encourage technology-
related professional development teaching style so that the teachers will feel more
comfortable in using of technology tools.
From my simulation of pendulum story, I can conclude that from the three factor which
affect the period of the pendulum, only the length of string does influence the period of the
pendulum. The longer the length of the string, the higher the period of the pendulum and thus
will lower the frequency. The initial displacement and mass of bob would give no effect to the
period of the pendulum. The initial displacement only gives effect to the amplitude of the
pendulum which is when the initial displacement increase, the amplitude of the pendulum
also will increase. Differ for the mass of bob where it does not gives any effect to the
amplitude, period and frequency of the pendulum’s motion.

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