---

Grade Level

9th Grade Physical Science — East Baton Rouge Tara High School, Louisiana

Duration

90 Minutes

---

Next Generation Science Standards (NGSS) Alignment

HS-PS2-6: Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.

HS-PS2-1: Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship among net force, mass, and acceleration (supports understanding electric forces and current as forces on charged particles).

HS-PS3-3: Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy (links electrical current flow and energy transformation).

This lesson supports Disciplinary Core Ideas (DCI) in PS3.B: Conservation of Energy and Energy Transfer (electric currents can transfer energy) and PS2.B: Types of Interactions (electric forces exert interactions on charged particles). Students will engage in science and engineering practices (SEP) of planning and carrying out investigations, analyzing and interpreting data, and constructing explanations and designing solutions.

---

I. Learning Objectives:

Students will be able to (SWBAT):

• I can describe electric current and identify the two types of current (Direct and Alternating).
• I can define and classify conductors and insulators, explaining why some materials conduct electricity better than others.
• I can explain factors that affect resistance in a circuit and relate resistance to material properties.
• I can explain how voltage creates electric current, using voltage as electrical pressure.
• I can calculate voltage, current, and resistance using Ohm’s Law (V = I × R) and represent problem-solving steps using the Ohm’s Law triangle.

---

II. Success Criteria

• Correctly describe and differentiate between AC and DC current, and identify examples.
• Accurately classify materials as conductors or insulators and justify classifications.
• Explain how length, thickness, material, and temperature impact resistance.
• Correctly apply Ohm’s Law formulas to solve for voltage, current, and resistance with at least 80% accuracy.
• Collaborate effectively in groups to solve real-world problems demonstrating understanding of Ohm’s Law.

---

III. Materials

• PowerPoint presentation with visuals and diagrams
• Whiteboard & markers
• Calculator (one per student or pair)
• Ohm’s Law triangle reference handout
• Group scenario cards with real-world problems
• Activity worksheets (vocab, calculation, reasoning)
• Exit tickets (short formative assessment)

Optional for demonstration/lab:

• Batteries, small light bulbs, wires
• Samples of metal paperclips, rubber bands, plastic strips, aluminum foil

---

IV. Lesson Sequence

A. Bell Ringer (5–7 minutes)

Objective: Activate prior knowledge and engage curiosity for upcoming content.

• Prompt on board:

  • What makes a charger work?
  • Why don’t we get shocked touching plastic?
  • Which materials conduct electricity best?

• Activity: Students pair-share answers for 3 minutes. Selected pairs share out loud with class. This energizes engagement for the upcoming lesson.

---

B. Introduction to Electric Current (10–15 minutes)

Objective: Understand electric current types and basic concept.

Teacher Explanation:

• Define electric current as flow of electric charge (electrons).
• Units: Amperes (Amps) - show symbol and explain measurement.
• Two types: Direct Current (DC)—electrons flow one way (e.g., batteries), Alternating Current (AC)—electrons reverse direction regularly (e.g., wall outlets).

Visuals: PowerPoint animations showing flow of electrons.

Real-Life Examples: Battery and wall outlets images/videos (drawing from YouTube references).

Check for Understanding: Quick Q&A:

• Which type do batteries produce?
• Which type powers your home?

---

C. Conduction & Materials (10 minutes)

Objective: Classify materials and understand conduction basics.

• Define conductor (allows flow of electric charge) vs insulator (does not allow flow).
• Classify metals (copper, aluminum)—good conductors; rubber, plastic—good insulators.
• Discuss wire coating as safety insulation.

Hands-on Demo [Optional]: Pass around different materials to touch and guess. Connect metal to light bulb circuit demo.

Discussion: Why is rubber used to coat wires?

---

D. Resistance (15 minutes)

Objective: Understand resistance and its influencing factors.

• Define resistance as opposition to electric current, unit: Ohms (Ω).
• Factors affecting resistance:
  1. Length: Longer wires resist current more.
  2. Thickness (cross-sectional area): Thicker wires resist less.
  3. Material: Some materials resist more.
  4. Temperature: Higher temperature increases resistance.

Analogies:

• Water pipe: Narrow pipes resist water flow, wide pipes let water flow easily.
• Hallway crowd: Packed crowd slows movement (high resistance).

Class Discussion: Why does a long wire resist more current?

---

E. Voltage & Current Relationship (10 minutes)

Objective: Define voltage and explore its relationship with current and resistance.

• Define voltage as electrical pressure pushing electrons through a conductor; unit: Volts (V).
• Explain: Higher voltage → higher current, but higher resistance → lower current.
• Illustrate formula conceptually before formal introduction of Ohm’s Law.

Guided Questions:

• What happens to current if voltage increases but resistance stays the same?
• What if resistance increases?

---

F. Ohm’s Law (20 minutes)

Objective: Use Ohm’s Law formula to calculate voltage, current, and resistance.

• Present Ohm’s Law: V = I × R.
• Explain each variable clearly:
  • Voltage (V) in volts
  • Current (I) in amperes (amps)
  • Resistance (R) in ohms (Ω)
• Introduce the Ohm’s Law triangle for problem-solving (hands-on visual aid).

Guided Practice: Teacher models 3 example problems:

• Solve for V given I and R.
• Solve for I given V and R.
• Solve for R given V and I.

Students practice three problems independently or in pairs, using calculators and triangle. Teacher circulates to assist.

---

G. Group Activity: Ohm’s Law Problem Solving (15–20 minutes)

Objective: Collaboratively apply understanding in real-world scenarios.

• Students split into groups of 3–4.
• Each group receives a scenario card describing common electrical problems (e.g., calculating battery voltage needed, resistance to dim a bulb, current flow in a wire).
• Groups solve problems, write down formula and work, and prepare a brief explanation to share.

Teacher Role: Facilitate collaboration and prompt groups to explain reasoning clearly.

Presentations: Groups present solutions and explanations (3 minutes each).

---

H. Independent Practice Worksheet (10–15 minutes)

Objective: Reinforce vocabulary, calculation skills, and conceptual understanding individually.

• Worksheet sections:
  • Vocabulary review (match terms and definitions)
  • Calculation practice (3–4 problems of varying difficulty)
  • Short conceptual reasoning question (e.g., "If resistance doubles, what happens to current? Explain.")

Teacher circulates, provides hints/scaffolding as needed.

---

I. Exit Ticket (5 minutes)

Formative Assessment: Students complete exit tickets independently.

Prompts:

• Define electric current.
• Identify AC or DC based on a description.
• Solve one simple Ohm’s Law problem provided.
• Explain how resistance affects current flow briefly.

Collected to assess understanding and guide next instruction.

---

V. Differentiation Strategies

Learner Need	Support	Extension
Short attention span	Hands-on group work, frequent engagement through questioning, varied activities	Challenge with multi-step problems, concept explanation to peers
English Language Learners (ELL)	Provide glossaries with pictures, sentence starters for explanations	Use scientific journals or articles linking electricity to technology
Struggling learners	Provide step-by-step scaffolding and formula triangle, access to partner support	Use visual models/analogies, extra practice with teacher
Advanced learners	Tackle conceptual extensions (e.g., effect of temperature on resistance in different materials), design circuits in simulation tools.	Research historical impact of Ohm’s Law on technology development

---

VI. Closure (5 minutes)

Review Key Takeaways:

• Electric current = flow of charge (electrons).
• Voltage provides the push—the electrical pressure.
• Resistance opposes the current flow.
• Ohm’s Law connects voltage, current, and resistance mathematically.

Real-World Connection:

• Electricians use Ohm’s Law to troubleshoot circuits.
• Engineers design efficient circuits for phones and appliances.
• Chargers use DC current to power devices safely.

Final Prompt: “Think about how this lesson impacts your daily use of technology. What new understanding do you have about the devices you use every day?”

---

Notes for Teacher

• Use engaging, colorful PowerPoint slides with animations showing electron flow and circuit diagrams to hold attention.
• Use YouTube videos (from references) as dynamic visual explanations but keep them short (2-3 minutes) to maintain attention.
• Encourage student discovery by prioritizing active problem solving and peer discussion over lengthy lecturing.
• Use the optional demo/lab materials for tactile learners and to anchor abstract concepts in concrete experiences.

---

This detailed plan directly aligns with NGSS by integrating crosscutting concepts (systems & models), engaging students in Science & Engineering Practices, and providing disciplinary core ideas about electric circuits and energy transfer. It balances conceptual understanding, mathematical application, and real-world relevance optimized for 9th graders with short attention spans and preference for hands-on, problem-solving activities.