Forces and Energy

Overview

Students explore how forces relate to energy by identifying energy as kinetic or potential, classifying forms of energy, and tracing energy transfers in simple scenarios. The lesson builds a clear model of energy definitions and uses simple equations (GPE = mgh and KE = ½ mv²) to support predictions and interpretation.

Learning intentions

Students will be able to:

• define energy and classify energy as kinetic or potential
• identify forms of potential energy (gravitational, elastic, chemical, nuclear) and give examples
• calculate gravitational potential energy and kinetic energy using formulas
• describe how energy transfers and transforms between kinetic, electrical, heat and sound energy in simple systems
• use a diagram (energy flow) to represent energy changes and check for anomalies

Success criteria

Students can:

• correctly sort at least 6 examples into kinetic or potential energy
• explain (in words) what changes energy from potential to kinetic and back
• calculate GPE and KE for given values and justify units
• create an energy-flow representation that includes at least two energy transfers and one energy transformation

Curriculum links

• AC9S8U05: classify kinetic and potential energy and investigate energy transfer and transformations in simple systems
• AC9S8I01: develop investigable questions, reasoned predictions and hypotheses to explore models and identify patterns
• AC9S8I04: select and construct representations (tables/graphs/energy flow diagrams) to organise and process information
• AC9S8I05: analyse data and information to describe patterns, trends and identify anomalies
• AC9S8I08: write and create texts using appropriate language to communicate findings (short explanation + diagram)

Lesson structure (60 minutes)

1. 0–6 min · Hook (energy in motion). Teacher shows 3 quick scenarios (rolling toy car, stretched rubber band, lit torch) and asks: “What energy is being stored or used?” Students turn and talk, then list one energy type for each scenario.

2. 6–16 min · Direct teach: energy definitions and classification. Teacher explains energy as the ability to cause change, then distinguishes kinetic (movement) and potential (stored) energy, using examples from the class brainstorm. Students complete a quick “Sort it” sheet: label each example as kinetic or potential and add a one-sentence reason.

3. 16–26 min · Potential energy focus + formula (GPE = mgh). Teacher models gravitational potential energy using a ramp scenario and writes GPE = mgh, discussing variables (m in kg, g in N/kg, h in m). Students practise with 3 data cards (mass and height provided), calculating GPE and stating whether energy is increasing or decreasing.

4. 26–36 min · Kinetic energy focus + formula (KE = ½ mv²). Teacher introduces kinetic energy as energy of motion and KE = ½ mv², emphasising that velocity (not just mass) affects KE and units. Students calculate KE for two masses at the same speed and compare results, recording the relationship as a short statement (“When v increases, KE changes by…”).

5. 36–50 min · Investigation stations: energy transfers (electrical, heat, sound). Teacher sets up 3 mini-stations with teacher oversight and clear safety notes:

• Station A: electrical to heat (filament light globe or heater on low setting)
• Station B: electrical to sound (small speaker/headphones linked to a phone tone)
• Station C: electrical to light/sound/heat combined (torch and small buzzer together if available) Students, in groups of 3–4, observe, record evidence (what they see/hear), then fill a simple table: “Input energy type → observed effects → likely energy transfer/transformation.” Teacher circulates and prompts linking back to kinetic/potential classification (e.g., “Is any potential energy involved before the circuit turns on?”).

6. 50–58 min · Energy flow diagram (representation and critique). Teacher demonstrates an energy flow diagram for one station (e.g., electrical energy in → heat/light/sound out), then shows a flawed example with a missing transfer for students to critique. Students create an energy flow diagram for their chosen station and add a short “What doesn’t match the evidence?” check for anomalies.

7. 58–60 min · Exit ticket. Students answer: (1) one definition of energy, (2) one example each of gravitational and elastic potential energy, (3) one energy transfer involving heat or sound.

Resources

• Scenario cards (rolling car, stretched rubber band, raised object, chemical battery, torch flame, nuclear as “stored in nucleus” model)
• “Sort it” student worksheet (kinetic vs potential)
• GPE and KE calculation cards with values (m, h, v) and units prompts
• Station equipment (choose appropriate items based on school access):
• filament globe/torch globe or small heater with a safe power source
• small speaker or buzzer with a phone/audio device or simple signal generator
• torch/battery power unit for combined effects
• Data recording table sheet for stations
• Energy flow diagram template (boxes/arrows) and marker pens
• Safety checklist for circuits and heat sources
• Exit ticket slips

Assessment

• Formative checks during the “Sort it” task: teacher listens for correct reasoning (movement vs stored)
• Accuracy check of GPE and KE calculations (units, substitution errors, comparisons)
• Station observation notes and energy-flow representations: teacher reviews for correct energy transfers and evidence alignment
• Exit ticket: determines readiness to move to more complex systems next lesson

Differentiation

• Support:
• sentence starters for explanations (e.g., “Gravitational potential energy increases when… because…”)
• worked example displayed step-by-step before independent calculations
• word bank for energy transfer terms: electrical, heat, sound, light, kinetic, potential
• Extension:
• challenge students to identify one likely energy transformation they did not include and justify why it might be smaller or harder to observe (e.g., electrical to sound vs electrical to heat)
• EAL/SEN:
• provide a visual version of formulas with units reminders
• allow oral responses during turn-and-talk and provide simplified station recording options (tick boxes + one short sentence)