Lesson 5: Collisions 5
Duration of Days: 2
Lesson Objective
1. Students will prove that when two objects crash, they push against each other with the exact same amount of maximum force (peak force), even if one object is much bigger or moving faster.
2. Draw a Free Body Diagram to look at each object by itself and show the hidden push-and-pull forces acting on it during a crash.
3. Explain how speed and weight (mass) change an object's kinetic energy (energy of motion).
4. Predict how a crash will change by showing that more kinetic energy creates a much harder hit (higher peak force) when objects collide.
How does changing the mass or speed of a moving object before it collides with another object affect the forces on those objects during the collision?
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
Description:
Students will test how speed and weight change the impact of a crash by rolling different carts into each other and measuring the exact moment of hardest impact—the "peak force." Using their data, students will draw specialized physics diagrams, called Free Body Diagrams, to map out how energy of motion (kinetic energy) transforms into equal, opposite crushing forces between the two colliding objects.
Purpose:
Students will discover one of the most surprising rules of science: when a giant truck hits a tiny parked car, they actually push on each other with the exact same amount of force. By understanding how speed, mass, and kinetic energy create these intense forces, students learn how engineers calculate crash data to design safer speed limits and stronger protective gear.
DOK 3
For English Language Learners (ELL) & Emerging Readers: Provide pre-labeled arrow cutouts or stickers for their Free Body Diagrams so they can focus on the direction and equal size of the force arrows rather than spelling the terms (e.g., matching a "Force of Cart A on Cart B" sticker to its arrow).
For Students Needing Extra Support (Scaffolding): Create a "Kinetic Energy Cheat Sheet" graphic organizer with simple up-arrows to reinforce the core pattern: More Speed = More KE = Higher Peak Force and More Mass = More KE = Higher Peak Force.
For Visual & Tactile Learners: Use spring-loaded scales or digital force sensors attached to two toy carts. Allow students to physically smash the carts together so they can see the digital graphs spike to the exact same maximum number simultaneously on both screens.
Formative Assessments