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MathTrax Rocket Simulation Tutorial

Includes Screen Reader Cues

The rocket simulation program is an application designed to teach a student about some of the many parameters and attributes that govern a rocket’s flight. The student should observe and note what effects on the attributes of the rocket flight result from the alteration of the parameters. In brief, the experience gained through operation of the rocket simulation program will allow the student to learn about a few of the intricacies of rocket flight.

Open the MDE application, enter alt+f, and you should hear “new”. Press the right arrow key, and you hear “rocket simulation”. Press enter on “rocket simulation”, and the rocket simulation application opens up to the rocket simulation settings. These settings include:

Each parameter has its given default setting value. The parameters can be changed to modify some feature in the trajectory, or the flight path, of the rocket. After you have made the alterations in the parameters, you can tab to one of three choices: Tab to “o.k”, and Press space bar to accept the new parameters you entered, tab to “default”, and press space bar to set the parameters to their original settings, before any changes were made,tab to “cancel”, and press space bar to exit the rocket simulation program.

Upon pressing space bar on “o.k”, you find yourself in the groupBox data file entry panel where you learn which data file is being used. Tabbing once brings you to the data file entry panel groupBox browse button wherein you can select or enter a data file for the rocket simulation application. Simply press the spacebar to open the list of data files from which to choose. You can select a new file by pressing spacebar on the data file of your choice, or work from the present file. The next six tabs will allow you to select the features of the trajectory you want to examine with respect to time. Those features are acceleration in meter per square second, altitude in meters, drag in newtons, flight angle in degrees, range in meters, and velocity in meters per second. You can choose one or more of the attributes to examine over the given .1 second time intervals, but one should note that that can be a lot of information to take in.

You can also get to the acceleration entry panel by entering control+f. as you tab through the remaining fields, pressing spacebar will either select or deselect the attribute for change; you can also enter control+k to select or deselect all the attributes. After selecting the attributes for change, you can tab to “rescale the graph and press the spacebar to fit the data”, or enter alt+t, which has the same effect.

Let’s say you want to select acceleration from the attribute list. Then you can enter control+f which you put you in the acceleration panel. Press spacebar to select acceleration. Now, enter control+d to go to the description panel in which a description of how the acceleration of the rocket changes in .1 second intervals over the given course of 72.64 seconds. If you desire to take a closer look at what is going on during the rocket’s flight, then you can tab until you arrive at the table which has 7 columns and 728 rows. Look through some of the values of the acceleration column of the table. Try to find the point where the rocket’s acceleration is the greatest within the first .5 seconds; can you determine why this is the case?

If you want to find the points at which the acceleration is at a local extremum, you can enter control+d to go to the description of the graph, and this will reveal to you the extremum points on the graph at the respective times. As to why acceleration has these values at the respective points, you have to consider the forces acting on the rocket and when they act on the rocket within the context of newton’s second law, f = ma.

The following exercise will giver you information on how to change the parameters for the rocket, but we will work directly with the time step parameter to see how changing it will give you different critical values. The lowest time step is .1, and so, you will get detailed information about the progression of the values for acceleration along the rocket’s trajectory. However, should you want to increase the time step, then you should enter alt+f, you should hear “new”; press right arrow key, press down arrow key until you hear “rocket simulation”, then press spacebar. This will return you to the first of the parameters, the time step panel. Delete the given value and enter the time step you desire, say .5 seconds. Enter control+f which returns you to acceleration, the first of the attributes. Tab until you get to the table. This should put you in the first column of the table. Press the down arrow key a few times, and note that the time step increases by .5 seconds. Now, enter control+home, press the right arrow key, and proceed to examine the acceleration column by pressing the down arrow key, and pay attention to the changes in it. Now, what is the greatest value for acceleration when 0

<.5<1.0 when for value lowest what> Now, again, return to the description panel by pressing control+d, and read what acceleration values the description of the graph gives for 0<.5<1.0. and> our next exercise will show you the simplicity of navigating the description panel of the graphing calculator should you choose several attributes to be graphed. Press control+f and you will be at the acceleration panel; it should already be selected. Tab to the altitude and press spacebar to select it. Finally tab to the drag panel, Enter control+d to go to the description panel, and read. Notice how the descriptions of the three different attributes are separated into three distinct paragraphs. REMEMBER:although the descriptions are separated into three paragraphs, and no matter how tempting it may be, you must not use the control+down arrow command to skip to the next paragraph. this will cause the Rocket Simulation program to freeze up.

Just as we did to look more closely at the rocket’s acceleration we enter control+f and tab until we get to the first row/column of the time step panel. Press right arrow twice to arrive in the altitude column, or three times to get to the the drag column where you can examine the values of the respective attributes with more scrutiny.

The purpose of this next exercise is to show the simplicity of attributing understanding to the sonification to one attribute of the Rocket Simulation program compared to the difficulty that accompanies ascribing understanding to the sonification of several attributes. Right now, we have three attributes selected; enter control+f to return to the acceleration panel. Press spacebar to deselect the acceleration attribute. Tab twice to the drag attribute and do the same. The altitude attribute remains selected. Enter control+s to place you at the sonify button. Press the spacebar to hear the sonification of the altitude attribute with respect to ttime. The sound you hear is one that suggests an ascent to a maximum point and then a descent, which is easy enough to determine for oneself.

Now, enter control+f to get back to the acceleration panel, press spacebar to select it. Tab to and Deselect the altitude attribute. Enter control+s and press spacebar to sonify the acceleration graph. Using the same directions as you did selecting the attributes of altitude and acceleration, select and sonify only the drag attribute. When sonifying only one attribute, it is a lot easier to understand the sonification of the graph.

Now, enter control+f to go to the acceleration attribute, select it; tab to the altitude and the drag attributes and select them. Enter control+s and press spacebar to sonify the graph of the three attributes together. After having heard the attributes sonified individually, can you determine the identifying graph sound associated to each attribute? If you can, then select more attributes and sonify them to find out what your limit to distinguishing them is.

Presently, the time step parameter is set to .5 second intervals; the exercise that ensues will teach you to zoom in on particular sections of the acceleration graph, examine it in detail,and thereby, detect its criticalpoints. First, enter control+b to go to the boundary settings; delete its current value and set left boundary at 0.0; tab past the bottom boundary to right boundary, and press the return key. You do not have to tab to the top boundary to enter a value. enter control+t to rescale the graph. Enter control+s to go to the sonify button and tab twice to get to the sounds control groupBox left-right slider button. Press the spacebar; listen to the sound. Then press the pagedown key until you have heard what you believe is the sound with the highest pitch. Enter shift+tab to go to the values panel and read what the x and y values are. Compare these values with the values obtained from the table. To do this, enter control+f which takes you to the acceleration panel; tab until you arrive at the table. Naviage to the acceleration column and godown the column to compare the values here with those obtained from the sounds control groupBox left-right slider panel. Were you close to finding the maximum acceleration during that first .5 second interval?

After you have explored a particular section of the acceleration graph by setting the boundaries accordingly, you can reset the graph by entering control+r. this will center the origin and return you to a graph of the full range of aacceleration values over the entire designated time period. This applies to the other attributes as well, but, right now, we are focusing on acceleration.

 
 


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+ NASA Official: Robert Shelton
+ Last Update: April 7, 2005
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