Students test whether air resistance affects a tossed object's acceleration, using iterative experiment design, uncertainty analysis, and scientific integrity practices over two lab sessions.
Experimentation Goals
These experimentation goals are most strongly represented in the explicit learning goals described above:
Student Decision Making
In this lab, students have the opportunity to:
Discovery
Determine results previously known to:
Duration
2 sessions of 2 hours/session
Equipment Required
Implementation Tips
Students must commit to ONE object for the full two-week investigation — groups that switch objects mid-stream lose focus and fall behind. In Week 1, the primary goal is a working experiment, not polished results. Most experimental designs don't survive first contact with the equipment, so push students to complete and test their design and do a rough analysis of initial data before leaving. Week 2 is for refinement and rigor.
Sonic rangers have a detection cone with minimum and maximum range limits. Students need hands-on time learning to position the sensor (facing up or down) and keep the object's trajectory within the detectable zone. Budget time at the start of Week 1 for this.
A key facilitation challenge: likely neither the "air resistance negligible" nor the "air resistance significant" model will cleanly fit student data. Be prepared for this. A productive response is to have groups brainstorm testable variables (drag, buoyancy, air currents) and divide up who tests what across the class. The instructor guide provides detailed predictions for each variable to help you guide discussions.
How This Fits in Your Course
This is the fourth and fifth lab in a 9-lab introductory physics sequence. It follows a three-week pendulum unit (Labs 1–3) in which students learn to measure and quantify uncertainty, reduce uncertainty through iterative methods, and compare data sets using the t' statistic. Students should arrive at this lab already comfortable with repeated measurements, standard uncertainty, and the t' comparison framework.
The tossed objects unit shifts the emphasis from measurement technique to experimental design, model testing, and scientific integrity. Where the pendulum labs provided more structure, here students design their own procedures and choose their own analysis approaches. This makes it a natural bridge between guided and open-ended investigation.
The lab that follows (Lab 6: Stretchy Objects) introduces research question formulation, and Labs 7–8 are fully student-designed investigations that culminate in formal presentations in Lab 9. The tossed objects unit prepares students for that independence: they practice designing experiments, iterating on methods based on data, presenting findings informally, and proposing new testable questions — all skills they will need when running their own investigations. The follow-up homework for Week 2 explicitly asks students to propose questions for their own future investigation.
Students should have concurrent or prior exposure to basic kinematics concepts (position, velocity, acceleration), though the instructor notes indicate that force concepts (free-body diagrams) are just being introduced and should not be assumed.
2025-04 (Au) 117-121 lab schedule.docx
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Rachel Scherr
Lauren Bauman
Adrian Madsen
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