Physics Course Competencies

The Physics course starts and repeatedly returns to the question, “What is light?”. This reasonable but seemingly limited question actually provides a framework for addressing all the central ideas of an introductory physics course. Through the “What is light?” lens, core science ideas such as experimental design, theory-development, force and motion, wave phenomena, electrostatics and magnetism, circuits, and quantum mechanics can be developed. Mathematical modeling, problem-solving skills, experimental design, and data collection are integrated throughout the course.

The main Physics competencies:

Quantitative Skills

Behavior of Light

Experimental Design and Theory-Building

Forces and Motion

Work, Power, Momentum, and Energy

Rotational Systems

Wave Phenomena

Electrostatics and Magnetism

Quantum Behavior

Electrical Circuits

Specific Competencies....

Quantitative Skills

1. Students can use course-prerequisite math skills reliably. Skills emphasized include equation-solving (linear, quadratic, basic trigonometric), scientific notation, Pythagorean theorem, and basic trigonometric relationships.
2. Reliably uses unit analysis by incorporating units in calculations to see that the expected units result.
3. Demonstrates a solid familiarity with the units commonly used in this course. Examples are Newtons for force, Coulombs for electrical charge, m/s² for acceleration, Joules and kilowatt*hrs for energy, Watts for power, Hertz for frequency, kilograms for mass.
4. Recognizes the efficiency of using conversion factors, and uses them reliably.
5. Can effectively use a graphing calculator in the context of the needs of this course. This includes, as examples, using the correct mode for angles, using inverse trigonometric functions, modeling 2-D motion using parametric equations, and using the “short, lazy, and reliable” form of scientific notation.
6. Can find the components of vectors.

Behavior of Light

1. Qualitatively and quantitatively describe the behavior of light, including reflection, refraction (Snell’s Law), total internal reflection, and critical angle.
2. Know what a normal line is, and how angles of reflection and refraction are measured.
3. Be able to determine the index of refraction for a light transition from one medium into another by observing the angles of reflection and refraction.
4. Can apply his or her understanding of light to data transfer using fiber optics and how/why we see rainbows.
5. Can perform speed-distance-time calculations with the speed of light.
6. Realizes that the speed of light is tremendously fast, but NOT infinitely fast.
7. Can identify the basic assumptions of Newton's particle theory of light.
8. Can derive the Newton's Particle Theory version of Snell's Law.
9. Can describe Foucault's experiment and explain its significance.
10. Can identify behaviors of light that suggest that it has a wave-like character.
11. Can explain a double-slit light interference pattern in terms of the wave theory of light, including deriving the double-slit interference equation.
12. Can explain that one prediction of Maxwell's equations is that self-sustaining, traveling teams of electric and magnetic fields can exist, and that they travel at the speed of light!
13. Can explain that some phenomena, notably the photoelectric effect, can NOT be explained assuming light is wave, but must have particle-like qualitites (photons).
14. Understands and can explain what is meant by the wave-particle duality of light.

Experimental Design and Theory-Building

*This forms the framework of our course. These ideas will be re-visited multiple times in several topical contexts, but most often as we make observations, design experiments, and build and alter our model of light.

1. Can reliably explain our development of a model by citing the key questions that we posed, describing key observations and/or experiments performed, and interpreting the results and how the results impacted our understanding.

Forces and Motion

1. Understand the relationships between position, displacement, velocity, speed, and acceleration.
2. Be able to set up and clearly identify reference frames when solving motion problems, and can explain the usefulness of doing so.
3. Define what vector and scalar quantities are and be able to give examples.
4. Given a position versus time graph, be able to sketch the corresponding velocity versus time graph. Given a velocity versus time graph, be able to sketch a corresponding position versus time graph.
5. Understand Newton's Laws of Motion and be able to set up and solve
   1. problems using these concepts.
6. Be able to draw free-body diagrams.
7. Know and be able to use Newton's Law of Gravitation, including knowing
   1. what objects feel the force and what direction the forces act.
8. Understand the relationship between force, weight, and mass.
9. Know and be able to use Coulomb's Law of Electrostatics, including knowing
   1. what objects feel the force and what direction the forces act.
10. Find the components of vectors both graphically (drawing) and quantitatively (using trigonometry).
11. Can add vectors graphically, by components, and by using the Law of Cosines.
12. Can find the direction of a vector (the angle) using inverse trigonometry.
13. Be able to solve problems involving frictional forces. (Static friction, kinetic friction, normal force, etc.)
14. Can solve problems involving uniform circular motion (centripetal acceleration and centripetal force).
15. Be able to write equations modeling the position and velocity of an object as a function of time for one- and two-dimensional situations.
16. Be able to use equations modeling the motion of an object to make predictions about the position and velocity of the object.

Work, Power, Momentum, and Energy

1. Realizes that many different relationships about the physical world can be imagined, but many of them are not particularly useful to pay attention to. However, work, power, momentum, and energy ARE very useful ideas.
2. Can perform calculations involving work. W=F*d. Recognizes when work is positive or negative.
3. Can describe power as the rate at which work is performed, or the rate at which energy is produced, or the rate at which energy is consumed. Units are Watts.
4. Understands the relationship between impulse and change in momentum.
5. Can find the momentum of an object or a (simple) system of objects. Recognizes that momentum is a vector quantity.
6. Recognizes that momentum can be an easier quantity to pay attention to when analyzing complex behavior such as collisions.
7. Can use the idea of conservation of momentum to solve problems.
8. Can solve problems involving kinetic energy. Recognizes that kinetic energy is the energy an object has due to its motion.
9. Can solve problems involving potential energy. Recognizes that potential energy is energy an object has due to its position. Knows there are different types of potential energy, such as gravitational, electrical, elastic, and chemical.

Rotational Systems

1. Realizes that all the relationships previously introduced in this course regarding translational motion (previous two competencies) and be modified slightly so they apply to rotational systems.
2. Can identify the quantities that are translational/rotational “partners”. Examples: force/torque, mass/inertia, linear position/rotational position, linear velocity/rotational velocity....
3. Can solve problems involving rotational motion.

Wave Phenomena

1. Recognizes that waves are a way for energy to travel, as distinct from the kinetic energy carried by a moving object.
2. Understand basic wave properties like amplitude, superposition, and interference (constructive and destructive). For periodic waves, know how frequency, wavelength, and wave velocity are related.
3. ***Several competencies connecting wave ideas and light behavior are listed under Behavior of Light.

Electrostatics and Magnetism

1. Recognizes that “fields” are real, physical entities that affect the space where they exist. (electric fields, magnetic fields, gravitational fields).
2. Knows the operational definition of an electric field and can solve problems involving field strength, force, and electrical charge.
3. Can draw electric field lines for point charges, dipoles, and parallel plates.
4. Knows that an electrical current has a magnetic field associated with it (right-hand rule): Oersted's experiment.
5. Knows that a changing magnetic flux through a loop of wire will cause an electric field to be produced in the wire, which will cause current to flow if the ends of the loop of wire are connected to an external circuit: Faraday's experiment.
6. Can describe the basic operations of electric motors and generators using his or her knowledge of the previous two items.
7. Recognizes the Tesla as a derived unit of magnetic field strength.
   1. (1 T = N/(A*m))
8. Can solve problems involving the force on a current-carrying wire in a magnetic field.
9. Can describe what quantities Maxwell's equations relate. (No expectation of performing calculations using Maxwell's equations.)
10. Can explain that one prediction of Maxwell's equations is that self-sustaining, traveling teams of electric and magnetic fields can exist, and that they travel at the speed of light!

Quantum Behavior

1. Can describe the photoelectric effect.
2. Can explain the significance of the photoelectric effect in terms of developing a theory of light.
3. Knows that a photon is a “particle” of light, and can perform calculations involving the energy, frequency, or wavelength of a photon.
4. Can describe the Compton effect and describe its significance (a photon has momentum even though it doesn't have mass). Can use p=h/lambda.
5. Can describe black-body radiation and the ultraviolet catastrophe.
6. Can explain Planck's weird assumption about black-body radiation and the significance of this discovery. (quantization of the energy in atoms; hints of quantum mechanics?!)
7. Recognizes de Broglie's contribution to quantum theory (If light, which we thought was a wave, can also act like a particle, can a particle act like a wave?), and can confirm if/how his idea was confirmed by experiment.

Electrical Circuits

1. Know the relationship between Work (energy), charge, and potential difference.
2. Understands that voltage is a measure of electrical potential difference.
3. Knows what an equipotential line is, and can calculate work done to move charges from one to another. (Primary purpose: provide a visual model of voltage and electric fields.)
4. Realize that electrical circuits typically include resistive, capacitive, and inductive components. Recognize that we typically explore circuits with only resistive components in this course.
5. Know Ohm’s Law (R = V/I, or V = IR) and be able to apply it to whole circuits, partial circuits, and individual components in circuits when necessary and appropriate. Recognize that Ohm’s Law is different than the definition of resistance, R = V/I. For materials that obey Ohm’s Law, R is a constant. The definition of resistance does not assume that R is a constant for a circuit component; it may very well change as the voltage (or current) changes.
6. Can reliably find equivalent resistances for resistors in series and resistors in parallel.
7. Can use Kirchhoff's Current Law and Kirchhoff's Voltage Law to analyze circuits.
8. Can measure specific voltages across and currents through components in electrical circuits. For resistive components, can use the data to calculate the resistance.
9. Be able to determine the power being provided by an electrical component (a battery, for example) or being consumed by an electrical component (a lightbulb or a radio, for examples) in an electrical circuit. P = IV = I²R = V²/R
10. Can build a basic one-switch circuit that controls a light and a two-switch circuit that controls a light (each switch can turn on or off the light no matter the position of the other switch.) using typical lab materials.
11. Gains experience building a one-switch circuit that controls a light using residential electrical materials (2-conductor cable w/ground, wiring box, switch, etc.) on a little stud wall.