Instructions For CBL Programs From Precalculus/Physics Course

The programs provided to students allow the student the ability to play "what if" math and science. That is to say, they have the freedom to change the variables in the lab to make and confirm conjectures about the lab activity. Therefore, students will always be given the opportunity to choose the number of data points to be collected and the time between each sample. Note: All programs require that LINKCK be installed on the calculator to run properly.

Program Instructions are available for:
GENERIC	GENCHOOS	GENDIST
GENDISTM	CHOOSE	DROPBALL
DROPCHOO	FENCE?CM	SMPULLEY
SMPULACC	LINKCK

Generic

Generic is designed to allow the use of up to two probes to be attached to the CBL at the same time. Run the program GENERIC. Select the number of probes (1 or 2) and select the probe type in the order they are plugged into the CBL ports. When using one probe, it must be placed in Channel 1. Using two probes, plug the probes into Channel 1 & Channel 2. Of course the motion detector must be placed into the sonic port. When using two probes, select the probe in Channel 1 first followed by the probe in Channel 2 or the motion detector. The TI-CBR (Ranger) may not be used in conjunction with another port without the appropriate cable to attach to the CBL.

After setting up the number and type of probes, select the number of data points to be sampled and the time interval between each sample data. See the chart below for more information about relative starting points. Recall that 99 is the max number of points on a TI-82.

Probe	# of Points	Time
Motion	99	0.02 to ?? sec
Sound	50	0.0002 sec
Light	99	0.00025 sec

In general, the faster the motion/data being collected, the fewer the points and the faster the sample time. This allows for adjustment to fit a variety of labs. We typically use collection times of 0.02 to 0.05 seconds for most motion labs. Temperature and humidity labs should be set to collect the number of points allowed for the given amount of total time. (Total Time= # of points * Time). If the amount of time to collect data is longer than 4-5 minutes, the calculator would time out and shut down. In this case, the calculator will display a message to run GENERGET when the CBL displays done. The data will automatically be recalled from the CBL and graphed, even if the CBL has been turned off. To get the data, make sure the CBL is turned on and connected with a link cable to the calculator. Run GENERGET and the data will graph.

Once all data has been collected, a message will display on the screen noting that time is in L1, the first probe is in L2 and the second probe (when used) is in L3. The graphs will be displayed on the screen after ENTER is pressed.

When the motion detector or CBR (Ranger) is used with the program GENERIC, motion is measured in meters away from the motion detector. Moving an object away from the motion detector will increase the distance measured. Please note that motion less than 0.5 meters from the detector may result in unsatisfactory graphs. See information on GENDIST and GENDISTM for other possible uses of the motion detector with specific types of graphs.

GENCHOOS

GENCHOOS allows the use of a single probe plugged into either Channel 1 or the sonic port (CBR plugs directly into calculator). This program has a CHOOSE feature built into it so that the user can select only a portion of the graph. Distance is measured away from the motion detector as positive with the motion detector being zero. Once the data is collected a message will appear telling the user to select the left and right bounds. Press ENTER at the message and the graph will be displayed. The trace function will be active. Use the left/right cursor keys to find the left bound/portion of the graph which is to be kept. Press ENTER. A vertical line will appear at this point. Use the cursor keys to move to the right point of the graph which is to be kept. Press ENTER at this point and another vertical line will be graphed. The calculator will transfer the data to be kept into L3 & L4. The selected portion of the graph will be displayed in a new window. The original data is still in L1 & L2.

GENDIST

GENDIST is designed to measure distances with a motion detector/ranger where the reference point or origin is not the motion detector. For example, if you want to reference the floor as zero with the motion detector at the ceiling. Motion away from the zero point and toward the detector is considered positive distance. In this manner, an object which is dropped will show a positive height falling toward the floor which is at a height of zero. The motion detector must be at a fixed point. Run the GENDIST program. Press ENTER with the object at the position which is to be the origin (reference point for measurements). The detector will determine the distance to the origin and record it. Select the number of points to be determined and the time interval (generally 0.2 to 0.5 seconds). Start the object in motion and press ENTER to record the graph. Movement away from the detector will show a negative slope to the curve while motion toward the detector will show a positive slope.

GENDISTM

GENDISTM works exactly like GENDIST above, with the exception that the motion detector is moving. For example, move the motion detector around a wheel pointed toward the floor. The reference point is the floor and the motion detector is moving in a sinusoidal pattern. Run the program GENDISTM and position the detector at a starting point for an initial height (center of a wheel). Press ENTER to record the height. Select the number of points and time interval generally 0.2 to 0.5 seconds). Start moving the detector and press ENTER to record the data. The is particularly useful in recording sine/cosine curve data.

CHOOSE

CHOOSE allows the user to select a portion of any graph which has data stored in L1 & L2. Run the program CHOOSE. A message will appear telling the user to select the left and right bounds. Press ENTER at the message and the graph will be displayed. The trace function will be active. Use the left/right cursor keys to find the left bound/portion of the graph which is to be kept. Press ENTER. A vertical line will appear at this point. Use the cursor keys to move to the right point of the graph which is to be kept. Press ENTER at this point and another vertical line will be graphed. The calculator will transfer the data to be kept into L3 & L4. The selected portion of the graph will be displayed in a new window. The original data is still in L1 & L2. GENCHOOS is a program which has the choose portion of the program automatically built into the end of the program.

DROPBALL

Dropball is a program specifically designed to measure the acceleration of a falling object with a motion detector. Connect the motion detector to the sonic port or connect the calculator to the CBR. Position the motion detector at or near the ceiling. Run the program DROPBALL. The program will first measure the distance to the floor. When the message appears, move all objects away from the motion detector and press ENTER. After the measurement of distance to the floor, the message will be displayed to press ENTER to collect data. Position an object at least 0.5 meters below the motion detector. Make sure to stand away from the motion detector and hold the ball with two hands moving the hands away from the motion detector when the ball is dropped. One individual should press ENTER to record the data. A second individual should drop the ball once the motion detector begins to click indicating data is being recorded. A graph of the data will appear. Time is stored in L1 (sec) and distance is stored in L2 (m). Run the program CHOOSE to select out the portion of data which you wish to keep. Make sure to choose a left bound where the ball has definitely started dropping and a right bound prior to the ball hitting the ground. This program can also be used to record a ball bouncing for exponential decay. Also, see DROPCHOO for a program which has the choose feature built into it.

DROPCHOO

DROPCOO is a program similar to DROPBALL, with three exceptions. First, the choose feature is built into the calculator. You don't have to run the program CHOOSE. Second, the program is designed to make a process physicists call linearization work properly. The data is shifted horizontally by the program so that the vertex of the ball dropping is at the origin. For an explanation of linearization and associated problems, see the modeling section. Finally, the DROPCHOO program is not designed to record data after a ball bounces for exponential decay equations. Connect the motion detector to the sonic port or connect the calculator to the CBR.

Position the motion detector at or near the ceiling. Run the program DROPBALL. The program will first measure the distance to the floor. When the message appears, move all objects away from the motion detector and press ENTER. After the measurement of distance to the floor, the message will be displayed to press ENTER to collect data. Position an object at least 0.5 meters below the motion detector. Make sure to stand away from the motion detector and hold the ball with two hands moving the hands away from the motion detector when the ball is dropped. One individual should press ENTER to record the data. A second individual should drop the ball once the motion detector begins to click indicating data is being recorded. A message will appear telling the user to select the left and right bounds. Press ENTER at the message and the graph will be displayed. The trace function will be active. Use the left/right cursor keys to find the left bound/portion of the graph which is to be kept. Press ENTER. A vertical line will appear at this point. Use the cursor keys to move to the right point of the graph which is to be kept. Press ENTER at this point and another vertical line will be graphed. The selected data will be analyzed and shifted horizontally to make the vertex occur at time equal zero and a graph of the selected data will appear. Time is stored in L1 (sec) and distance is stored in L2 (m).

FENCE1CM and FENCE5CM

The FENCE programs are designed to record the motion of a picket fence passing through a photogate. To determine the width of the fence, measure from the start of one picket to the start of the second picket. Use FENCE1CM for a one centimeter picket fence and FENCE5CM for a five centimeter picket fence. Plug the photogate into Channel 1 of the CBL and connect the CBL to the calculator. Run the appropriate program. A message will be displayed telling the user to press ENTER to arm the photogate. Press ENTER and the calculator will display READY . . .. Release the picket fence to record the data. A graph with quadratic regression line will be displayed. Press ENTER and the home screen will show the values of a, b, and c for the regression and the acceleration which is twice the "a" value. The data is stored in L1 (sec) and L2 (m).

LINKCK

LINKCK is a program designed to test the CBL and connections. If a connection cannot be made, an error message will be returned. Most programs on these pages require that LINKCK be installed on the calculator.

SMPULLEY and SMPULACC

SMPULLEY and SMPULACC are designed for use with a 10 spoke inside Vernier smart pulley. The data collected is a distance (m) vs time (sec) graph. Connect the CBL to a photogate. Position the photogate so that the spokes of the pulley break its beam. Run the program SMPULLEY or SMPULACC. The time is determined by entering the number of revolutions of the smart pulley for which data is to be collected. Make sure that the sampling is completed prior to hitting the stop at the end of the ramp. A message will be displayed to press [ENTER] to arm the photogate. Position the string over the pulley and position the object. Press [ENTER]. Release the object. Time starts when the first spoke passes through the photogate and distance is zero at this point. SMPULLEY provides a distance (m) vs. time (sec) graph. The program SMPULACC works exactly the same as SMPULLEY with one additional feature. Press [ENTER] at the completion of the graph and the quadratic regression will be calculated. The values of "a", "b", and "c" will be displayed along with the acceleration. Note: The acceleration is twice the value of "a" in the regression equation.