Time Frame
1 class periods of 60 minutes each
Summary
Students will use a CBR (TI-Ranger) to measure the speed of a falling object. They will see how air resistance slows the speed of a paper coffee filter as compared to a book. They will also measure books of different sizes to discover the speed of falling objects is not dependent on the mass of the objects unless air resistance is a factor.
Materials
per group:
- 1 TI-73 Calculator and Ranger
- one coffee filter
- 2 books of different thicknesses
- student worksheet (attached)
Student Prior Knowledge
Students will need to know and be able to use the formula for calculating speed and have had some experiences measuring moving objects.
Instructional Procedures
- Read the introduction with students and describe where the materials for the activity are located.
- Pre-program the calculators to take a 3 second reading in meters. Set the start key for "trigger".
- Hand out the calculators and Rangers to students and allow them to take some readings of a moving object.
- Discuss what the graphs mean. A time vs. distance graph will show speed at any given point and the points can be traced with the curser.
- Read procedures with students and give them time to collect data.
- Discuss with class their results.
Assessment Plan
Scoring guide:
1. Students test each object 3 times……………………………………..4
2. Students graph a line for each object…………………………………4
3. Students answer analysis questions correctly……………………….4
- The coffee filter should go more slowly.
- The air holds it up or air resistance.
- The two books should travel about the same speed?
- The books were the same size(maybe) but different masses
- This experiment should proved Galileo to be correct.
- Gravity
4. Student writes and thoughtful and thorough conclusion…………….4
Bibliography
Lesson Design by Jordan School District Teachers and Staff.
Created: 10/29/2014
Updated: 02/01/2018
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