🏆 Unit: The Truth of Collisions —
Non-contact Energy Transfer

The Mission

PE

4-PS3-3: Ask questions and predict outcomes about the changes in energy that occur when objects collide.

DCI

● PS3.A Definitions of Energy: The energy of a moving object is related to its mass and its speed.

● PS3.B Conservation & Transfer: Energy can be transferred from place to place by moving objects or through collisions, which changes the objects’ motion.

● PS3.C Energy and Forces: When objects collide, force is the medium for energy transfer. In magnetic systems, this is demonstrated through field interactions.

SEP

● Asking Questions: Students observe non-contact collisions and ask: "How does energy travel through empty space?"

● Predicting Based on Evidence: Predict displacement outcomes based on changes in input velocity or object mass.

CCC

● Cause and Effect: Changes in energy input directly lead to changes in output.

● Energy and Matter: Energy flows and transforms between objects.

1-Minute Quick Experience

Quick Experience Detail

Scientific Argumentation (CER Model)

After completing observations, students synthesize the data into a logical scientific argument:

Claim:

Energy travels through magnetic fields without contact. The final motion depends on the input speed (energy) and the target mass.

Evidence:

Non-contact: Module B moves without being touched.
Speed: A "Fast Strike" results in larger displacement than a "Slow Drift."
Mass: Heavier modules travel less distance with the same input.
Transformation: Attracting modules "click" (sound/heat) instead of sliding.

Reasoning:

1. Invisible Bridge: Fields are the "pathway" energy takes to travel across empty space.
2. Potential Energy: Repelling fields act like invisible springs, storing energy and then "kicking" objects into motion (Kinetic Energy).
3. Energy Budget: Energy is a finite resource. A heavier mass "costs" more to move, resulting in less displacement for the same "price" (input).
4. Conservation: Module A stops because it transferred its energy to Module B or transformed it into sound and heat. Energy was traded, not lost.

Supplemental Inquiry Resources

Downloadable materials to support classroom implementation and student assessment.

Experimental Setup & Assembly

The course is divided into three phases, guiding students from observation to quantitative prediction.

Phase 1: Kinetic Energy and Field Force (Foundational Exploration)

Activity 1: The Speed Factor

Setup: Compare a "slow approach" vs. a "fast strike" from Module A toward Module B.

The "Slow Drift": Module B starts to move as soon as it feels a tiny bit of force. It "drifts" away lazily because the energy transfer is spread out over time.
The "Fast Strike": Module A’s momentum carries it deeper into the strong magnetic field before Module B has time to move. This "compresses" the field more intensely, resulting in an explosive transfer.

Activity 2: The Invisible Spring (Potential Energy)

Setup: Force Modules A and B together (repelling poles) and then release.

Focus: Feel the magnetic resistance. Understand that energy can be temporarily "stored" in the magnetic field and then converted into powerful kinetic energy.
Phase 2: The Variables of Impact

Activity 3: The Mass Factor

Setup: Attach a weight (e.g., penny, dime) to Module B and repeat the collision.

Focus: By maintaining the same energy input, students observe that a heavier object results in less displacement, demonstrating the inverse relationship between mass and acceleration.

Activity 4: Inelastic Collision

Setup: Flip Module A's polarity to attraction. Observe the "snap" as they jump together.

Focus: Energy transformation. As objects accelerate, potential energy converts to kinetic. Upon impact, it transforms into sound (the "click") and trace thermal energy.
Phase 3: Energy Flow and Vector Motion (Optional Tasks)

Activity 5: Magnetic Chain Reaction

Setup: Align Modules A, B, and C. Slide A toward B to trigger a sequential collision.

Focus: Build a "Flow Model" to visualize how kinetic energy travels through multiple objects, demonstrating that energy transfer is a continuous process.

Activity 6: Vector Thrust Challenge

Setup: Position A and C to approach B simultaneously at a 120-degree angle.

Focus: While energy is a scalar, the forces are vectors. Predict the path of B by understanding how multiple impacts combine to determine final direction.

CER Model: Evidence-Based Scientific Argumentation

After completing observations, students must connect their findings using the following logical framework:

C
CLAIM

Energy transfers across space via Non-contact Fields (the "Invisible Bridge"). The resulting motion (displacement) is determined by the Kinetic Energy of the input and the Mass of the object being moved.

E
EVIDENCE

● Non-contact Transfer: Module B moves when Module A approaches, even without physical contact.

● Speed Factor: A "Fast Strike" results in significantly larger displacement than a "Slow Drift."

● Mass Variable: Adding weights (coins) to Module B decreases its displacement, even when the energy input from Module A remains constant.

● Transformation: In attracting collisions, the kinetic energy of motion is replaced by a "click" (Sound Energy) and a trace of heat (Thermal Energy) upon impact.

R
REASONING

1. The Invisible Bridge (Fields): Energy does not require a solid medium to travel. In this system, the Magnetic Field serves as the pathway, allowing kinetic energy to cross empty space.

2. The Invisible Spring (Potential vs. Kinetic): Energy can be stored or active. When magnets repel, the field acts as an "Invisible Spring" storing Potential Energy. A "Fast Strike" overcomes the field's resistance to compress this spring more intensely, releasing a larger burst of Kinetic Energy.

3. The Energy Budget (Mass & Conservation): Energy is a finite "budget." Moving a larger Mass requires more energy; therefore, with a fixed input, a heavier object will always travel a shorter distance.

4. The Energy Hand-off (Conservation): When Module A slows down or stops, it is not "losing" energy—it is transferring it. The total energy in the system remains constant, whether it is handed off to move Module B or transformed into sound and heat.