Section 2: View |
| |
| On the right, there is a sample calculator screen. |
| |
| In the World (top portion of the image), there are two boxes to which we will refer to as "Cars." And there is a position ruler (labeled "DISTA" for Distance) with various tick marks, to help the user see how far the Cars have moved in the World. In our example here, each minor tick represents 1 unit and the major ticks appear every 5 units. (There are various ways to find out this information, which we will focus on later.) The dotted line represents zero. The Car above will be called Car A and the Car below, Car B. |
 |
| |
| Below the World region is a Graph region. Above is a Position graph, which can be deduced by the label or the motion. In this example, there are two graphs defined by y=2x on a domain [0, 6], and y=x on a domain [0, 2]. |
| |
| Animation Menu |
| The function keys just below the calculator screen open various menus, like the F1: File Menu that you use to load an activity in MathWorlds. We refer to the keys as F1, F2, etc. To enable our animation, we will use the F2: View: Animation Menu. |
| |
 |
The picture to the left shows the options available in F2: View. |
| |
 |
F2: View: Animation allows you to start the animation. When you select Animation, you will see the World and a flashing time cursor on the y-axis in the Position graph. A "play" icon in the upper right-hand corner indicates that you can run the animation. If you press Enter, the Actors will move and the vertical time cursor will sweep across the graph highlighting how far the actor has moved with respect to time. During animation, the Play icon will change to a Pause icon. Pressing Enter while the animation is playing will pause your Actor’s motion. |
| |
| While in Pause Mode, pressing the right or left arrow keys will step you through the animation. Your Actor will move according to the Step Time determined in F4: Tools: Clock. If at any time you wish to exit Animation, press 2nd QUIT [MODE]. |
| |
|
F2: View: Graph  POS allows you to view the Position graph (if available). This availability is document specific, meaning that its availability depends upon the intention of the document creator.
F2: View: Graph VEL allows you to view the Velocity graph (if available). This availability is document specific.
F2: View: Graph ACCEL allows you to view the Acceleration graph (if available). This availability is document specific. |
| |
 |
F4: Tools: Marks allows you to turn your Actors’ marks Off or On. They are dropped according to the Step Time determined in F4: Tools: Clock. |
| |
 |
F4: Tools: Clock allows you to set the start and end time of the animation. The Step Time, in this example, is 1 second, so pressing the left or right cursor keys in a paused animation will move the time cursor 1 second to the left or right. The Actor will move with respect to the position function defined at that time. |
| |
| Tool Tip |
| To end animation or to use other menus, press 2nd QUIT. |
| | |
| Dropping Marks |
 |
Here, both Cars drop a Mark every second. The Marks point in the direction of the motion. In this case, both Cars move from left to right, they do not go backwards. (If the cars went backwards, the Marks would point from right to left and may overlap previous marks.) Marks give us another representation of rate and slope-as-rate. In this case, the Marks are an equal distance apart every second. Since we are dropping a Mark every second, then this describes distance covered per second, which is the velocity of the Car and the slope of the Position graph. This would be a visual way of interpreting m in y=mx+b. Think about how changing the Step Time affects the Marks. The position of the Actor at the start of the animation helps deduce a value for b in y=mx+b. |
| |
| Another way to explore motion with animation is to use the Numeric Display, which shows Time and Position data for the elevators as they move. To use the Numeric Display, press F4: Tools, select NumDisp , use the right arrow, and then select "On." A display will appear at the bottom of the screen with three columns. The first is time, the second is A’s position, and the third is B's position. |
| |
 |
On the left, we have turned on the Numeric Display and are running the simulationa—we are 2 seconds into the simulation. Notice that the Time is given by the Vertical Time Cursor—which sweeps across the display when the animation is running—and also by the Numeric Display. The Numeric Display tells us that the Time is 2.0 seconds and that Car A is at 4 feet and Car B is at 2 feet. The position of the Vertical Time Cursor, the location of Marks, and the Numeric Display all work together, or in different combinations, to tell you something about the motions of the Actors. |
| |
 |
Finally, you can view a tabular representation of the Position data, and further derivatives of such data such as Velocity and Acceleration by selecting F4: Tools: Table . |
| |
 |
You can select the time you wish to start the table and what you want the Step Time in seconds to be. In the example on the left, start time is t=0 and the Step Time is one second. This can be linked to the Step Time during the animation. |
| |
 |
Here is the resulting tabular representation. The dashed lines correspond to points when the Actor’s function is not defined. Press 2nd QUIT [MODE] to exit the view. |
| |
|
|
