Activity Overview
In this activity, students will use a light sensor to collect intensity data for fast and slow variations of intensities. They will then describe these variations using the concepts of period and frequency.
Before the Activity
Connect the light sensor to Channel 1 on the CBL 2™ or Vernier LabPro®
Connect the CBL 2 or LabPro to the calculator using the Unit-to-Unit cable
See the attached PDF file for detailed instructions for this activity
Print pages 237 - 243 from the attached PDF file for your class
During the Activity
Distribute the pages to your class.
Follow the Activity procedures:
Method 1:
Point the sensor toward a light source and begin data collection
Use the thumb to cover and uncover the light sensor at one-covering-per-second rate
Observe the graph of light intensity versus time
Determine the period and frequency of the cover-uncover function
Method 2:
Point the sensor toward a fluorescent light source and recorded intensity every 0.0005 seconds
Examine the light intensity versus time plot
Determine the period and frequency of the pattern from the fluorescent light
Model the data using an absolute value sinusoidal equation
calculate the flicker frequency
After the Activity
Students will analyze the data and fill in the Data Collection and Analysis Sheet. They also answer the questions listed in it.
Review student results
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary