Students use the CBR 2™ to study how a change in mass affects the average speed of a falling object. They graph distance as a function of time, and interpret and analyze graphs representing motion.
Before the Activity
Connect CBR 2 to the calculator.
Launch the Ranger application
See the attached PDF file for detailed instructions for this activity
Print pages 35 - 36 from the attached PDF file for your class
Transfer files to student calculators using TI-Navigator™ "send to class" feature
During the Activity
Distribute the pages to your class.Hold the CBR 2 at eye level 0.5 meters directly above the concave side one coffee filter
Drop the filter and start recording distance - time data
Graph the data with time on the horizontal axis and distance from CBR 2 on the vertical axis
Understand what different sections in the graph represent
Repeat the experiment using 5 filters stacked together
Examine the Distance-Time plot and see that the stack of 5 coffee filters fell with the highest average speed.
Increase in mass caused the speed to increase
Follow the Adventure procedures:
Load the activity settings file CBRonFloor.act
Students mark points to illustrate what the plot of the coffee filters falling would have looked like if the CBR 2 had been placed on the floor and the filters released above it
Students also redraw for other conditions
After the Activity
Students analyze the results and answer the questions in the worksheetAs a class, discuss average speed, terminal velocity, and air resistance
Re-teach concepts as necessary
Review student results: