Nano PHYSICS . MECHANICS . MOMENTUM AND COLLISIONS . CENTER-OF-MASS MOTION

Explosions and Collisions

Explosions and collisions change relative motion, but the COM follows external forces only. Learn fragment motion, recoil reasoning, and why the COM path stays smooth.

Physics · Mechanics · Momentum and Collisions · Center-of-Mass Motion · Explosions and Collisions
Access for this nano-lesson
Unsigned visitors can show & copy prompts for Steps 1-3. Signed-in free accounts can also Run with AI for Steps 1-2. Paid accounts unlock everything (Steps 1-6 + Help prompts + AI).
Steps 1-3 Free Steps 4-6 Paid
STEP 1
Orient: explosions and collisions
Free
Establish center-of-mass motion as the motion of a system's mass-weighted representative point.
Prompt preview will appear here.
Goal: define COM motion using system choice, total mass, external force, and physical meaning.
STEP 2
Conceptual grounding: build the COM-motion model
Free
Build a workflow for systems, total mass, external force, internal forces, total momentum, and frame choice.
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Goal: distinguish individual-object motion from center-of-mass motion.
STEP 3
Real-world connection: interpret systems, frames, and relative motion
Free
Apply COM-motion reasoning to isolated systems, collisions, explosions, recoil, and reference-frame changes.
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Goal: explain isolated-system COM motion, COM-frame reasoning, collisions, explosions, and recoil in physical contexts.
STEP 4
Check your understanding: diagnostic mini-quiz
Paid
Attempt each question before revealing the COM-motion reasoning.
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Goal: identify and correct internal-force, external-force, recoil, frame, and collision-path errors before they become calculation errors.
STEP 5
Practice: solve increasingly rich COM-motion situations
Paid
Apply the model to situations that grow in complexity.
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Goal: write concise, physically justified COM-motion calculations and explanations.
STEP 6
Summary & reflection + explorations
Paid
Consolidate the model and explore changing external forces, systems, masses, velocities, frames, and recoil setups.
Prompt preview will appear here.
🔒 ▶ Explore interactive simulation
Goal: carry the model forward into collisions, explosions, recoil, center-of-mass frames, and system momentum analysis.