20
G
ETTING
S
TARTED WITH THE
CBR 2™
S
ONIC
M
OTION
D
ETECTOR
©
2000
V
ERNIER
S
OFTWARE
&
T
ECHNOLOGY
Activity 3—A Speedy Slide
(cont.)
Parabolic
c. Select
Edit
(press
q
) to open the
Sample Interval
dialog
window.
d. Enter 0.2 to set the time between samples in seconds.
e. Select
Next
(press
q
) to advance to the
Number of
Samples
dialog window.
f.
Enter 25 to set the number of samples. Data collection will
last for 5 seconds.
g. Select
Next
(press
q
) to display a summary of the new
settings.
h. Select
OK
(press
s
) to return to the main screen.
Í
Take your preliminary data-collection positions.
a. One member of the group should first go up the slide steps and sit at the top of
the slide.
b. A second person, while holding the
CBR 2™
motion detector, should go high
enough on the slide steps to hold the
CBR 2™
motion detector behind the person
who will slide.
c.
The third person should stand on the ground next to the slide, while holding the
calculator and interface.
Î
Take your final data-collection positions.
a. The slider, while holding on, should move forward enough to allow a 15-cm
distance between his or her back and the
CBR 2™
motion detector.
b. The person holding the
CBR 2™
motion detector should hold the
CBR 2™
motion
detector steady and aim it at the slider’s backside.
c.
The person holding the calculator and interface should move to a comfortable
position that does not cause a pull on the
CBR 2™
motion detector cable.
Ï
Collect
data.
a. Select
Start
(press
q
) to begin data collection.
b. The slider should begin to slide as soon as a clicking is heard.
c.
When data collection is done for this trial, the person with the
CBR 2™
motion
detector should come down to the ground.
Caution:
No student should attempt to pass another person while he or she is on
the steps.
