NetLogo User Community Models
by Matthew Colebeck (Submitted: 11/29/2006)
WHAT IS IT?
This is a model that will simulate Newton's Second Law of Motion which states "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object."
HOW IT WORKS
This model works by using the input of Force and Mass from the user. On the plot of Acceleration, ( Force / Mass ) which is acceleration, is plotted on the y-axis and time on the x-axis. As the user increases or decreases either the force or mass, then that is outputed on the Acceleration plot, so that the user can see that as either the force or mass is changed, the acceleration will also change.
HOW TO USE IT
Hit the Setup button, and that will place a square and an arrow onto the graph. The user can decide what color they would like these two turtles to be. The user must now decide whether he/she plans on keeping the force constant. If the user wants to keep the force constant, he/she can leave that "ON". Now hit go! The turtles will start to move, and then the acceleration will be plotted. Since the force is held constant, that means that the user will change the mass of the square turtle. So, as the mass increases, the acceleration will decrease; this will be seen by the slowing of the turtles as well as the "Acceleration" plot. If the user decreases the mass, then the acceleration will increase, and this will be shown by the increase in turtle movement and on the "Acceleration" plot.
If the user wouldn't like to keep the force constant, then he/she can it "OFF". Now hit go! The same procedure will occure again, but this time as the user increases the force, that means that acceleration will increase. The user will see an increase in speed of turtles, as well as an increase on the "Acceleration" plot. If the user decreases the force, that means that the acceleration will decrease. The user will see this effect as the turtles will slow down and see a decrease on the "Acceleration" plot.
During this whole time, an output of the calculated acceleration will be shown in an output text. This output text will so the exact acceleration of the object at that specific time.
THINGS TO NOTICE
Notice how Newton's Second Law works!
Notice how the turtles will increase or decrease as the acceleration increases or decreases!
Notice the output text box of the acceleration of the turtles!
Notice how the user can change the colors of the square and arrow turtles!
THINGS TO TRY
EXTENDING THE MODEL
This is pretty much a complete model, there isn't much more to add.
Notice in the Procedure tab how I have written code to have the turtles move using an "ifelse" statement.
CREDITS AND REFERENCES
A special thanks to the class of LAI 532.
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