Activity Overview
In this activity, students will use a light sensor to record the light intensity at various distances from a bulb. They will compare the data to an inverse square and a power law model.
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 157 - 162 from the attached PDF file for your class
During the Activity
Distribute the pages to your class.
Follow the Activity procedures:
Arrange the sensor and the light bulb for data collection
Dim the lights to darken the room
Move the sensor away from the light source in 1 cm increments and study the graph of light intensity versus distance
Trace the graph, record the left-most x and y values on the Data sheet, and calculate the initial model parameter
Use these values to model a best fit function for the inverse-square model and the power law model
After the Activity
Students will complete the Student Data Collection and Analysis Sheet and 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