Lesson 9: Collisions 9
Duration of Days: 2
Lesson Objective
1. Students will investigate the hidden forces (like friction and air resistance) that slow down a moving object before it even hits a target.
2. Explain how friction works as a contact force caused by microscopic bumps on surfaces rubbing and pushing against each other.
3. Prove that friction and air resistance always push back in the exact opposite direction of an object's motion.
4. Track how energy transfers into heat (particle-level kinetic energy) when two surfaces rub together.
5. Critique and improve scientific models based on feedback from classmates to show how energy leaks out of the launcher system.
How do other contact forces from interactions with the air and the track cause energy transfers in the launcher?
collision
force
kinetic energy
damage
contact force
deform
line of best fit
elastic limit
breaking point
Independent variable
dependent variable
peak force
free body diagram
concussion
axon
stored (potential) energy
air resistance
friction
MS-PS2-1
MS-PS2-2
MS-PS3-1
MS-LS1-8
MS-ETS1-2
MS-ETS1-3
Lesson Description:
Students will investigate why moving objects eventually slow down on their own, looking closely at how invisible factors like friction and air resistance steal energy from their launcher systems. By examining surfaces under magnification and debating ideas with their peers, students will update their physics models to show how rubbing surfaces create a backwards-pushing force that transforms kinetic energy into heat.
Purpose
Students will discover why a rolling skateboard eventually stops or why their hands feel warm when they rub them together. By understanding that friction and air resistance are actual contact forces that turn motion energy into heat, students learn the engineering principles behind why cars need oil, why planes are aerodynamic, and how energy is never truly lost—it just changes form.
DOK 3
For English Language Learners (ELL) & Emerging Readers: Provide a visual "Opposites Match" card game or graphic organizer that pairs a motion arrow going one way with a labeled friction/air resistance arrow pointing the exact opposite way.
For Students Needing Extra Support (Scaffolding): Provide a sentence frame checklist for the peer-feedback session so students can give constructive critiques safely (e.g., "Your model clearly shows _, but I think you should add an arrow for _ because...").
For Kinesthetic & Sensory Learners: Have students vigorously rub an eraser against their desk or rub their hands together for 15 seconds so they can physically feel the mechanical energy turning into thermal energy (heat) before trying to model it.
Formative Assessments