|
The following is a three week unit plan given during the third quarter. This plan illustrates
how the 5E-Model is used, and how the experiments, lectures, quizzes, and tests fit together.
To see smaller plans that consist of either two days or two weeks, click below:
Two Day Plan
Two Week Plan
Electro-Statics and Circuit Unit
1. Unit Title: Electro-statics and Circuits
2. Unit Length:
Duration: 3 weeks
Session: 47 minutes
3. Grade Level: 11-12
4. Science course: Physics
5. Unit Overview:
Purpose:
The students will gain an understanding of electric force and its strength and place relative to the other three fundamental forces in the Universe. Furthermore, they will understand how electric fields, electrical potential energy, and potential difference govern the movement of electric charges as well as the parallels between these concepts and those found with gravitational fields and potential energy.
This will lead into to current and circuits. The students will understand Ohm's law and Kirchhoff's rules and how they apply to circuits in series and in parallel. They will be able to reduce any circuit into one resistor and examine the current paths along with voltage drops. In addition, they will be able to reduce circuits into one capacitor, and understand their role in circuits.
Activities:
Demonstration with plastic wand and Styrofoam disc.
Demonstration with Electroscope.
Computer Simulation experiment to investigate the relationship between electric force, distance, and charges.
Demonstration with Van De Graff Generator.
Computer simulation experiment to investigate electric field lines and their affects on test charges.
Two-page research paper on Charles Coulomb and Michael Faraday.
Computer simulation experiment to investigate the relationship between voltage and current.
Computer simulation to investigate circuits in parallel.
Two-page paper on Andre Marie Ampere.
Unit expectations:
This unit fulfills the expectation of the course as outlined in the course catalog and syllabus and state standards.
Unit Importance:
Electric force and its consequences along with a basic knowledge of circuits are covered in both the National and State of Kansas Science Standards as items student should understand after completing a physics course.
6. Unit Outcomes:
The students will understand the following items.
Like charges repel, opposite charges attract.
Relative sizes between electrons and protons.
Coulomb's Law: the relationship between electric force and distance between charges, and the product of the charges.
Strength of electric force compared to gravity and the other three fundamental forces in the Universe.
Understand how to use Coulomb's Force Law equation.
Rutherford's work in determining the atomic structure.
Electric field lines and strength associated with charges and shapes as well as the fact the electric field inside objects is zero.
Parallel between F = QE and F = mg.
Electric potential energy associated between two charges and its parallel to gravitational potential energy.
Potential difference and its affect on electrons, and applications to circuitry.
How to reduce any type of circuit and find the total current, current paths, and voltage drops.
How to reduce capacitors in a circuit, and their role in circuitry.
7. Unit Organizer: Not Available.
8. Materials:
Plastic Wand and Styrofoam ring
Electroscope
Van De Graff Generator
Computers with Simulation Software
9. Instructional Plan:
Engage
Day One: Introduction of Electric Force. Students will participate as a class.
Demonstration of plastic wand and floating Styrofoam ring.
Introduce electric force and demonstrate the electroscope.
Move an electrically charged rubber rod to the scope and observe the hanging flaps.
Question: why are the flaps moving apart?
Explain an induced dipole.
Question: what will happen if the rod touches the scope?
Make the point that it is the electrons that move, not the protons.
Further demonstrate the movement of electrons with the Van De Graff Generator.
Question: when you walk across the carpet and touch a doorknob or another person, why is there a shock?
Compare the sizes and charges of electrons to protons.
Have students develop a hypothesis of the following question: What is the relationship between electric force and the distance between the charges, and the two charges themselves.
Explore
Day Two: Computer simulation experiment to investigate electric force. Students will be in groups of three to four.
The students will take data on the electric force between two charges at varying distances.
The students will also take data on the electric force between two charges with varying charges.
The students will use Microsoft Excel to graph the data in order to interpret the results.
Explain
Day Three: Coulomb's Law. Students will participate as a class.
As a class, we will examine the graphs and determine the relationship between electric force and the distance and charges.
Introduce Coulomb's Law equation and the constant K comparing it with the Universal gravitation equation.
Question: Which of the four forces in the Universe is the strongest? The weakest?
Do a problem that compares the electric force with gravitational force.
Question: where does electric force come from? How about gravity.
Introduce the concept of electric fields.
Day Four: Electric Fields. Students will participate as a class.
Show example of electric field lines for like charges, and opposite charges.
Cover the rules for electric fields.
Show electric fields for parallel plates, and solid objects.
The electric field inside an object is equal to zero.
Introduce the electric field equation and show example of how to compute a charge's electric field and how it affects another charge.
Do example that finds where the electric field between two charges is equal to zero.
Elaborate
Day Five: Computer simulation experiment with electric fields. Students will be in groups of three or four.
The students will further investigate how the electric field lines of a charge predict the direction of another charge at a certain point.
The students will practice using the electric field equation to compute the electric forces on charges.
Evaluate
Day Six: Quiz. Students will participate as a class.
The quiz will cover the information from last week.
We will go over the quiz in class.
Engage
Day Seven: Electric Potential Energy. Students will participate as a class.
Demonstration with pith balls enclosed in a box with a plastic cover that is rubbed with rabbit's fur. Discuss why the balls are moving.
Explain
Begin with reviewing the gravitational potential energy and how it gives kinetic energy.
Introduce the concept of electric potential energy and how it causes charges to move.
Introduce the electric potential equation and how it predicts the velocity of charges.
Compare the relationship of potential to distance with electric force and distance.
Elaborate
Day Eight: Potential Difference. Students will participate as a class.
Tie into yesterday's discussion about potential energy, and how a difference in energy between two points will cause electrons to move.
Show example of a vacuum tube and how it relates with a t.v.
Engage
Demonstration of a light source connected to different potentials.
Discuss the direction of electrons and how one gets electrocuted when touching a fence with a certain voltage.
Question: Would you get hurt if your hands and feet were touching the same potential?
Introduce circuits and how a potential difference or voltage is utilized to create a current.
Discuss the components of circuits and the two things needed for a circuit.
Introduce the concept of a resistor and its function in a circuit.
Have the students make a hypothesis on the relationship between voltage and current.
Explore
Day Nine: Computer simulation experiment on voltage and current. Students will be in groups of three to four.
The students will take data on a circuit. When they have a certain resistance, they will vary the voltage and record the resulting current.
They will graph their results and take the slope of their graph to see that it equals the circuit's resistance.
Explain
We will discuss the results and introduce Ohm's Law.
I will show them the waterfall analogy to demonstrate how they relate, and what determines the danger in touching a live circuit.
Day Ten: Series and parallel circuits. Students will participate as a class.
Do an example of reducing a series circuit by adding resistors in series. They will find the total current and voltage drops.
Explain voltage drops across resistors and their relation to the energy of the electron.
Do an example of reducing a parallel circuit by adding the resistors in parallel. They will find the total current, and current paths as well as the voltage drops.
Question: which circuit would result in the larger resistance, series or parallel?
Question: Why do more electrons choose the path with the smallest resistor?
Explain why the path with the least resistance has the most electrons or current.
Evaluation
Day Eleven: Quiz. Students will participate as a class.
The quiz will cover the information from last week.
We will go over the quiz in class.
Day Twelve: Capacitors. Students will participate as a class.
Discuss the function of capacitors and where they are found in modern electronics.
Show how to add capacitors in series and parallel.
Question: In which case is the most energy stored, parallel or series?
Explain how a capacitor in a circuit with a resistor works.
Cover the time constant.
Show the graphs of charging and discharging.
Question: Where would you need to store energy for a circuit?
Discuss their applications to modern electronics.
Elaborate
Day Thirteen: Computer simulation experiment with circuits. Students will be in groups of three to four.
The students will work with a series and parallel circuit breaking them down to find total current and voltage drops.
Evaluation
Day Fourteen and Fifteen: Test.
The students will take a test over the last three week's worth of material.
10. Assessment Plan:
The students will be graded on the following:
Two-page paper on Coulomb and Faraday as outlined in the research paper guidelines.
Two page paper on Ampere.
A written lab report over Coulomb's law experiment as outlined in the lab report guidelines.
A written lab report over Ohm's law experiment as outlined in the lab report guidelines.
Two lab packets completed in class.
Two quizzes.
Unit Test.
11. Safety Plan:
The only cause for concern would be the Van De Graff Generator. The students will be told to be careful around the globe, and a discharge wand will be used to keep the charge manageable.
Take me to the Assessment section
Full list of References. |