Physics Priority Expectations - Detroit Public Schools

Physics Priority Expectations

describing motion

energy transformations

forces and motion

mechanical energy

momentum

periodic motion

gravity

Note about the sequence and organization of units in this document: The sequence of units in this document is based on the Physics HSCE Companion Document. It has been slightly revised in several ways, to strengthen the overall sequence. The two units in the companion document that addressed motion of objects were combined into one, and a separate unit on gravity was created. The unit on energy transformations, which was placed in the companion document toward the end, was moved to the beginning as an overall introduction, since energy considerations appear everywhere in physics. And the last unit in the companion document, called “Energy and Society,” was streamlined to address the overview of nuclear physics, with other HSCEs about energy transformations moved to appropriate units. The purpose of this document is to help you organize your curriculum based on the big ideas and core concepts of each unit. We hope you find these suggestions helpful.

8

mechanical waves

electric forces

nuclear physics

electromagnetic waves

electric circuits

Within each unit, Content Expectations are identified as “Priority Expectations” or as supplements to the priority expectations—meaning extensions or applications. The extensions and applications are clustered under the priority expectations, to show how ideas fit together within units. Some of the HSCEs have been slightly reworded, to enhance the clarity of their meaning. A list of reworded HSCEs with their original wording is provided at the end of this document. In the future, we hope to provide web resources to allow teachers to expand on the “Inquiry, Reflection and Social Implications” examples provided here, as well as the “Instructional Examples” provided in the Companion Document. Scientific Inquiry, Scientific Reflection and Social Implications The section in each unit on Inquiry, Reflection and Social Implications uses abbreviations for those HSCEs. The complete list can be found at the end of the document.

| ISD/RESA/RESD Collaborative • High School Physics Priority Expectations

The Big Ideas in the Physics Units Energy Transformations

Unit 1

Energy is transferred between objects during interactions and frequently transformed from one type to another in mechanical, electrical and natural systems. The total amount of energy remains constant in closed systems. Motion (including Two Dimensional)

Unit 2

The motion of an object may be represented using motion diagrams, tables and graphs, and mathematical functions. Solving problems about motion is facilitated by using functions. Dynamics

Unit 3

When two objects interact with each other, by direct contact or at a distance, all three of Newton’s Laws describe and explain that interaction. Momentum

Unit 4

A moving object has a quantity of motion (momentum) that depends on its velocity and mass. In interactions between objects, the total momentum of the objects does not change. Periodic Motion

Unit 5

Periodic motion describes objects that oscillate back and forth or move in a circle. These motions are quantified by their period or frequency. Gravity

Unit 6

Unit 7 Unit 8

Gravity is one of four fundamental forces of nature, the attractive force between any two masses. It explains why objects fall to the Earth and why planets and satellites stay in their orbits. Mechanical Energy The amount of energy transferred when an object is moved is equal to the work done on the object. Mechanical Waves Mechanical waves are vibrations in a medium that move from source to receiver, conveying energy. Electromagnetic Waves, Visible Light and Optics

Unit 9

Electromagnetic waves transfer energy and information from place to place without a material medium, and visible light is a form of electromagnetic radiation. All electromagnetic waves move at the speed of light in a vacuum. Electric Forces

Unit 10

Unit 11

All objects are composed of electrical charges. The electric and magnetic forces are the result of the strength and motion of charges. Most interactions in everyday life (other than gravity) are the result of electric and magnetic forces. Electric Current Electric current is used to transfer energy and to do work. Nuclear Physics

Unit 12

Radioactive decay is the spontaneous transmutation of one nucleus into another with the release of high energy particles. Nuclear fission and nuclear fusion create new elements and release high energy particles and massive amounts of radiation.

ISD/RESA/RESD Collaborative • High School Physics Priority Expectations | 9

Unit 1

Energy Transformations

energy transformations

INVOLVE

energy transters into and out of system

OCCUR BETWEEN

ARE GOVERNED BY

law of conservation of energy

various forms of energy

Big Idea Energy is transferred between objects during interactions and frequently transformed from one type to another in mechanical, electrical and natural systems. The total amount of energy remains constant in closed systems.

Inquiry, Reflection and Social Implications: P1.1A P1.1D P1.1E

Generate questions for investigations Relate patterns in data to theories Give evidence to support conclusions Students can generate questions such as “Where did the energy go?” using various phenomena that illustrate energy transfer, like dropping a ball or swinging a pendulum and noticing that they don’t return to their starting point, or shaking a jar of sand with a thermometer inserted; they can then identify patterns in data and describe reasons to support their conclusions.

P1.1f

Predict results of changes in variables Students can predict what would happen if variables are changed in investigations using various physics simulations such as “Energy Skate Park” at http://phet.colorado.edu.

Core Concepts •

Friction in mechanical systems limits the amount of energy that can be converted to useful work.

•

In most energy transfers, some energy is inadvertently transformed into heat which warms the surroundings.

10 | ISD/RESA/RESD Collaborative • High School Physics Priority Expectations

Content Expectations

(Priority Expectations are highlighted in gray.)

P4.3A

Identify the form of energy in given situations (e.g., moving objects, stretched springs, rocks on cliffs, energy in food). (i.e., Give examples of KE, GPE, CPE, EPE.)

P4.1A

Account for and represent energy into and out of systems using energy transfer diagrams.

P4.3C

Explain why all mechanical systems require an external energy source to maintain their motion.

P4.2f

Identify and label the energy inputs, transformations, and outputs, using qualitative or quantitative representations, in simple technological systems (e.g., toaster, motor, hair dryer) to show energy conservation. (application)

P4.11a

Calculate the energy lost to surroundings when water in a home water heater is heated from room temperature to the temperature necessary to use in a dishwasher, given the efficiency of the home hot water heater. (application)

P4.11b

Calculate the final temperature of two liquids after they are combined, given their initial temperatures and masses (same or different materials). (application)

P4.2A

Account for and represent energy transfer and transformation in complex processes (interactions).

P4.10A

Describe the energy transformations when electrical energy is produced and transferred to homes and businesses. (application)

P4.10B

Identify common household devices that transform electrical energy to other forms of energy, and describe the type of energy transformation. (application)

P4.2B

Name devices that transform specific types of energy into other types (e.g., a device that transforms electricity into motion). (application)

P4.2C

Explain energy conservation in common systems (e.g., light incident on a leaf, mechanical energy in a collision).

P4.2D

Explain why all the stored energy in gasoline does not transform to mechanical energy of a vehicle. (application)

Unit 1


Unit 2

Motion

motion can be

DESCRIBED BY

position over time, velocity, acceleration

REPRESENTED BY

motion diagrams, tables and graphs, funcations

Big Idea The motion of an object may be represented using motion diagrams, tables and graphs, and mathematical functions. Solving problems about motion is facilitated by using functions.

Core Concept •

DEPENDS ON

Motion is relative to whatever frame of reference is chosen.

frame of reference

Inquiry, Reflection and Social Implications P1.1C P1.1D P1.1f

Conduct scientific investigations Relate patterns in data to theories Predict results of changes in variables Students can measure, graph, and analyze motion using photogates, motion detectors, etc. They can predict how a motion graph might change if, for example, velocity changes in a certain way, and test their predictions.

P1.2C Access information from multiple sources A great video for illustrating frames of reference is “Virtual Insanity” by Jamiroquai, available on YouTube.




P2.1A

Calculate the average speed of an object using the change of position and elapsed time.

P2.1B

Represent the velocities for linear and circular motion using motion diagrams (arrows on strobe pictures).

P2.1C

Create line graphs using measured values of position and elapsed time.

P2.1D

Describe and analyze the motion that a position-time graph represents, given the graph.

P2.1g

Solve problems involving average speed and constant acceleration in one dimension.

P2.2A

Distinguish between the variables of distance, displacement, speed, velocity, and acceleration.

P2.2B

Use the change of speed and elapsed time to calculate the average acceleration for linear motion.

P2.2C

Describe and analyze the motion that a velocity-time graph represents, given the graph.

P2.2e

Use the area under a velocity-time graph to calculate the distance traveled and the slope to calculate the acceleration.

P2.2g

Apply the independence of the vertical and horizontal initial velocities to solve projectile motion problems.

P2.3a

Describe and compare the motion of an object using different reference frames.

Unit 2


Unit 3

Dynamics Newton’s Laws govern interactions

FIRST LAW

an object in motion stays in motion...

When two objects interact with each other, by direct contact or at a distance, all three of Newton’s Laws describe and explain that interaction.

•

Law 1: Unbalanced forces cause changes in motion (speed and/or direction).

•

Law 2: The size of the change is directly proportional to the force and inversely proportional to the mass of the object.

•

Law 3: Whenever one object exerts a force on another, a force equal in magnitude and opposite in direction is exerted back on it.

equal and opposite reaction

F=ma

Big Idea

Core Concepts

THIRD LAW

SECOND LAW

Inquiry, Reflection and Social Implications P1.1A Generate questions for investigations P1.1h Design and conduct investigations; draw conclusions P1.1D Relate patterns in data to theories Students can use simple equipment like model cars and rubber bands to develop the relationship between force, mass and acceleration. They can pose and answer the question “How does changing the force affect the acceleration?” They develop ways of measuring acceleration. P1.1f

Predict results of changes in variables Students can use dynamics experiments, such as rolling a ball down a ramp and off a table, to make predictions about how changes in variables will affect motion.

P1.2f Critique solutions to problems P1.2g Identify tradeoffs in designs The West Point Bridge Designer software (free— Google it) helps students visualize multiple forces. It stimulates good discussions of constraints and tradeoffs in design decisions.




P3.2A

Identify the magnitude and direction of everyday forces (e.g., wind, tension in ropes, pushes and pulls, weight).

P3.1A

Identify the force(s) acting between objects in “direct contact” or at a distance.

P3.1d

Identify the basic forces in everyday interactions.

P3.2C

Calculate the net force acting on an object.

P3.2d

Calculate all the forces on an object on an inclined plane and describe the object’s motion based on the forces using free-body diagrams. (application)

P3.4B

Identify forces acting on objects moving with constant velocity (e.g., cars on a highway).

P3.3A

Identify the action and reaction force from examples of forces in everyday situations (e.g., book on a table, walking across the floor, pushing open a door).

P3.4A

Predict the change in motion of an object acted on by several forces.

P3.4C

Solve problems involving force, mass, and acceleration in linear motion (Newton’s Second Law).

P3.4e

Solve problems involving force, mass, and acceleration in two-dimensional projectile motion restricted to an initial horizontal velocity with no initial vertical velocity (e.g., a ball rolling off a table).

Unit 3


Unit 4

Momentum collisions between objects

CONSERVE

momentum (mass x velocity)

IMPART

force over time (impulse)

Big Idea A moving object has a quantity of motion (momentum) that depends on its velocity and mass. In interactions between objects, the total momentum of the objects does not change.

Core Concept •

EQUAL TO

change in momentum

Inquiry, Reflection and Social Implications P1.1A P1.1E P1.1f P1.1g

A small force over a long time can produce the same change in momentum as a large force over a short time. (This can be derived from Newton’s Second Law.

Generate questions for investigations Give evidence to support conclusions Predict results of changes in variables Critique reasoning based on evidence Students can investigate P3.4g in many ways: •

• • • • P1.2i

Drop a tennis ball and basketball together, tennis ball resting on top of basketball, and observe how the tennis ball rebounds Compare an egg thrown into a sheet vs. thrown into a wall Play catch with water balloons Jump off a table with straight vs. bent knees Bungee jump vs. string jump with a force meter attached to the top of the cord

Explain progressions of ideas An understanding of momentum is the basis for understanding advanced scientific research such as collisions in particle accelerators. Students can begin to see how a simple understanding of momentum can be applied in more complex ways to more complex phenomena.




P3.4f

Calculate the changes in velocity of a thrown or hit object during and after the time it is acted on by the force. (application)

P3.4g

Explain how the time of impact can affect the net force (e.g., air bags in cars, catching a ball).

P3.5a

Apply conservation of momentum to solve simple collision problems.

P3.3b

Predict how the change in velocity of a small mass compares to the change in velocity of a large mass when the objects interact (e.g., collide).

P3.3c

Explain the recoil of a projectile launcher in terms of forces and masses. (application)

P3.3d

Analyze why seat belts may be more important in autos than in buses. (application)

Unit 4


Unit 5

Periodic Motion periodic motion

may be constant throughout period

acceleration points inward

bicycle wheel or Earth in orbit

SPEED

SPEED

TYPE

TYPE REPRESENTED BY

period: time to complete one cycle

Big Idea Periodic motion describes objects that oscillate back and forth or move in a circle. These motions are quantified by their period or frequency.

Core Concept •

changes throughout period

Centripetal force is the force holding an object in circular motion; it points radially inward. The force we perceive when riding on an object moving in circular motion that pushes us outward is called centrifugal force, a fictitious force that results from our accelerated frame of reference. In fact, it is a result of our inertia, which tends to move us forward in a straight line, tangential to the circular motion.

wing or other pendulum

net force on object determines acceleration

Inquiry, Reflection and Social Implications P1.1A P1.1D P1.1f P1.1h

Generate questions for investigations Relate patterns in data to theories Predict results of changes in variables Design and conduct investigations; draw conclusions Students can experience and investigate acceleration in circular motion on amusement park and playground rides, generating questions, collecting data, predicting results of changes in variables and designing tests of their predictions, relating patterns in data to concepts of acceleration in circular motion. They can do the same as they investigate motion of pendulums and weighted springs. Accurate measurement techniques need to be devised to minimize measurement error.

P1.1g Critique reasoning based on evidence P1.2f Critique solutions to problems Use the Projectile Motion simulator at http://phet. colorado.edu to let students investigate changes in speed and direction and critique the reasoning behind these concepts based on their evidence. This is good practice for the citizenship duty of applying evidence and reason to social policy decisions. 18 | ISD/RESA/RESD Collaborative • High School Physics Priority Expectations



P2.1E

Describe and classify various motions in a plane as one dimensional, two dimensional, circular, or periodic. (definition of terms)

P2.1h

Identify the changes in speed and direction in everyday examples of circular (rotation and revolution), periodic, and projectile motions.

P2.1F

Distinguish between rotation and revolution and describe and contrast the two speeds of an object like the Earth. (application)

P2.2D

Explain how uniform circular motion involves acceleration without a change in speed.

P2.2f

Describe the relationship between changes in position, velocity, and acceleration during periodic motion.

P3.4D

Identify the force(s) acting on objects moving with uniform circular motion (e.g., a car on a circular track, satellites in orbit). (Links to Unit 6, Gravity)

Unit 5


Unit 6

Gravity

gravity

IS

attractive force between two masses

OBEYS

inverse square law

Big Idea Gravity is one of four fundamental forces of nature, the attractive force between any two masses. It explains why objects fall to the Earth and why planets and satellites stay in their orbits.

Core Concept •

EXPLAINS

FELT AS

circular and elliptical orbits

weight of object on Earth

Inquiry, Reflection and Social Implications P1.1D P1.1E P1.1f P1.1g

Relate patterns in data to theories Give evidence to support conclusions Predict results of changes in variables Critique reasoning based on evidence Using the Gravity Force Lab at http://phet.colorado.edu, students can make predictions about what will happen if the masses and/ or distance between objects are changed, relating patterns in the data to the universal law of gravitation. In class discussions, they can give evidence to support their conclusions and critique reasoning based on the evidence.

P1.2i

Explain progressions of ideas The theory of gravity and solar system explorations are two excellent case studies for looking at the progression of ideas that lead to current scientific knowledge.

The force of gravity is directly proportional to the product of the masses of the two bodies and inversely proportional to the square of the distance between them.




P3.1A


P3.6B

Predict how the gravitational force between objects changes when the distance between them changes.

P3.6A

Explain earth-moon interactions (orbital motion) in terms of forces. (application)

P3.6C

Explain how your weight on Earth could be different from your weight on another planet. (application)

P3.6d

Calculate the force, masses, or distance between two bodies, given any three of these quantities, by applying the Law of Universal Gravitation, given the value of G.

P3.6e

Draw arrows (vectors) to represent how the direction and magnitude of a force changes on an object in an elliptical orbit. (application)

Unit 6


Unit 7

Mechanical Energy

engergy transfer in interactions

VARIOUS SITUATIONS

work in sliding an object on the ground: W=Fd

work in moving an object uphill W=mgh

Big Idea The amount of energy transferred when an object is moved is equal to the work done on the object.

Core Concept •

In mechanical systems, W = F d, where d is in the same direction as F. This is a convenient equation when the object is moved against the force of friction, with no acceleration. When the object moves freely, the work done is equal to its change in KE.

work in accelerating an object W=1/2mv2

Inquiry, Reflection and Social Implications P1.1A P1.1D P1.1f

Generate questions for investigations Relate patterns in data to theories Predict results of changes in variables Energy Skate Park at http://phet.colorado.edu is good for simulating transformations of GPE to KE. Students can generate questions to investigate, identify patterns in data and analyze them using their knowledge of how to calculate GPE and KE, and make and test predictions. Turn on the pie chart, and set friction >0, to investigation transformations to heat.




P4.1c

Contrast the everyday meaning of “work” with the more precise scientific meaning. (reworded)

P4.1d

Calculate the amount of work done on an object that is moved from one position to another.

P3.2A

Compare work done in different situations. (application)

P4.1B

Explain instances of energy transfer by waves and objects in everyday activities (e.g., why it hurts when you are hit by a baseball).

P4.1e

Using the formula for work, derive a formula for change in potential energy of an object lifted a distance h. (application)

P4.3B

Describe the transformation between potential and kinetic energy in simple mechanical systems (e.g., pendulums, roller coasters, ski lifts).

P4.3e

Calculate the changes in kinetic and potential energy in simple mechanical systems (e.g., pendulums, roller coasters, ski lifts, using the formulas for kinetic energy and potential energy).

P4.3d

Calculate the amount of kinetic energy of everyday examples of moving objects. (revised slightly) (application)

P4.2e

Explain the energy transformation as an object (e.g., skydiver) falls at a steady velocity. (application related to Unit 1)

P4.3f

Calculate the impact speed (ignoring air resistance) of an object dropped from a specific height or the maximum height reached by an object (ignoring air resistance), given the initial vertical velocity.

Unit 7


Unit 8

Mechanical Waves

mechanical waves

EXAMPLES

water waves, earthquakes, sound

TRANSFER

AS CHARACTERIZED BY

energy, not matter

PROPAGATE

frequency and wavelength, which are inversely proportional

Big Idea Mechanical waves are vibrations in a medium that move from source to receiver, conveying energy.

Core Concepts •

Sound waves are compression waves (longitudinal), while water waves are transverse waves.

•

Waves can be described by their frequency or wavelength, which are inversely proportional, and by their speed and amplitude.

•

Waves created by a point source travel outward in all directions, decreasing in intensity with the square of the distance from the source.

•

Waves can interfere constructively or destructively.

through a medium, unlike EM waves

RESULTING IN

interference patterns

Inquiry, Reflection and Social Implications P1.1f Predict results of changes in variables P1.2C Access information from multiple sources Students can use Slinkies to study both transverse and compression waves and interference patterns, changing variables and predicting results. There are good wave simulations at http://phet.colorado. edu, including Waves on a String and Wave Interference. The Tacoma Narrows Bridge Collapse video dramatically illustrates resonance (http://www.youtube.com/watch?v=3mclp9QmCGs).




P4.1B

Explain instances of energy transfer by waves and objects in everyday activities (e.g., why the ground gets warm during the day, how you hear a distant sound).

P4.4A

Describe specific mechanical waves (e.g., on a demonstration spring, on the ocean) in terms of wavelength, amplitude, frequency, and speed.

P4.4B

Identify everyday examples of transverse and compression (longitudinal) waves. (application)

P4.4C

Compare and contrast transverse and compression (longitudinal) waves in terms of wavelength, amplitude, and frequency. (application)

P4.4d

Demonstrate that frequency and wavelength of a wave are inversely proportional in a given medium.

P4.4e

Calculate the amount of energy transferred by transverse or compression waves of different amplitudes and frequencies (e.g., seismic waves). (extension)

P4.5A

Identify everyday examples of energy transfer by waves and their sources. (application)

P4.5B

Explain why an object (e.g., fishing bobber) does not move forward as a wave passes under it. (application)

P4.5C

Provide evidence to support the claim that waves transfer energy, not matter. (slightly revised) (application)

P4.5D

Explain how waves propagate from vibrating sources and why the intensity decreases with the square of the distance from a point source.

P4.5E

Explain why everyone in a classroom can hear one person speaking, but why an amplification system is often used in the rear of a large concert auditorium. (application)

P4.8c

Describe how two wave pulses (e.g., propagated from opposite ends of a demonstration spring) interact as they meet.

P4.8d

List and analyze everyday examples that demonstrate the interference characteristics of waves (e.g., dead spots in an auditorium, whispering galleries, colors in a CD, beetle wings). (application)

Unit 8


Unit 9

Electromagnetic Waves, Visible Light, and Optics electromagnetic waves

CHARACTERISTICS

frequency, wavelength, speed of light

radio, microwave —transmission

Big Idea Electromagnetic waves transfer energy and information from place to place without a material medium, and visible light is a form of electromagnetic radiation. All electromagnetic waves move at the speed of light in a vacuum.

TYPES AND USES

visible light, infrared—optics

Inquiry, Reflection and Social Implications P1.1A P1.1D P1.1f

Generate questions for investigations Relate patterns in data to theories Predict results of changes in variables Students can generate questions, test predictions, identify patterns and relate them to theoretical models using optics experiments. For example, a laser can be used with various transparent materials to collect data on refraction and test Snell’s Law.

P1.2j

Predict effects of technology Simple communications devices can be constructed in the lab, such as a modulated laser and electronic eye used to transmit voice. This kind of design and building process can give students insight into the use of scientific principles to anticipate effects of technological design decisions.

Core Concepts •

Light waves reflect, scatter, refract and interfere with each other in ways similar to mechanical waves.

•

Our perception of color is a result of the color of light incident on an object and the colors that are reflected and absorbed by the object.

x-rays—medical uses; safety concerns




P4.6A

Identify the different regions on the electromagnetic spectrum and compare them in terms of wavelength, frequency, and energy (recognizing that all EM waves travel at the same speed in a vacuum).

P4.6B

Explain why radio waves can travel through space, but sound waves cannot. (application)

P4.6C

Explain why there is a time delay between the time we send a radio message to astronauts on the moon and when they receive it. (application)

P4.6D

Explain why we see a distant event before we hear it (e.g., lightning before thunder, exploding fireworks before the boom). (application)

P4.6e

Explain why antennas are needed for radio, television, and cell phone transmission and reception. (application)

P4.6f

Explain how radio waves are modified to send information in radio and television programs, radiocontrol cars, cell phone conversations, and GPS systems. (extension)

P4.6g

Explain how different electromagnetic signals (e.g., radio station broadcasts or cell phone conversations) can take place without interfering with each other. (extension)

P4.6h

Explain the relationship between the frequency of an electromagnetic wave and its technological uses. (extension)

P4.9B

Explain how various materials reflect, absorb, or transmit light in different ways.

P4.9C

Explain how scattering accounts for atmospheric phenomena (e.g., blue sky, red sun at sunset).

P4.8A

Draw ray diagrams to indicate how light reflects off objects or refracts through transparent media.

P4.8B

Predict the path of reflected light from flat, curved, or rough surfaces (e.g., flat and curved mirrors, painted walls, paper). (application)

P4.8e

Given an angle of incidence and indices of refraction of two materials, calculate the path of a light ray incident on the boundary (Snell’s Law).

P4.8f

Explain how Snell’s Law is used to design lenses (e.g., eye glasses, microscopes, telescopes, binoculars). (application)

P4.9A

Identify the principle involved when you see a transparent object (e.g., a piece of glass) in a clear liquid. (application)

Unit 9


Unit 10

Electric Forces

electric forces exist between charged objects

MAGNITUDE

as with gravity, electric forces obey inverse square law

INTERACTIONS

as with magnetic poles, like charges repel and unlike charges attract

charge can be induced on an object

Big Idea All objects are composed of electrical charges. The electric and magnetic forces are the result of the strength and motion of charges. Most interactions in everyday life (other than gravity) are the result of electric and magnetic forces.

Core Concepts •

Electric and magnetic forces obey the same inverse square law that governs gravitational interactions.

•

Positive electric charges are carried by protons, while negative electric charges are carried by electrons. Electrostatic charge on an object, both positive and negative, is the result of the addition or removal of electrons only.

some objects can acquire an excess electric charge

example: balloon rubbed on a wall

Inquiry, Reflection and Social Implications P1.1B Evaluate conclusions P1.1E Give evidence to support conclusions Students can investigate static electric charges and the forces between them using a van de Graaf generator, hair, pith balls, electroscopes, balloons, acetate and vinyl strips, etc. Students can use their observations to construct a model of forces on electric charges. P1.2g Identify tradeoffs in designs Students can understand and critique technological solutions to problems involving electric charges, such as the need for computer technicians to ground themselves when working with electrically sensitive computer parts.




P3.1A


P3.1b

Explain why scientists can ignore the gravitational force when measuring the net force between two electrons. (application)

P3.1c

Provide examples that illustrate the importance of the electric force in everyday life. (application)

P3.7A

Predict how the electric force between charged objects varies when the distance between them and/or the magnitude of charges change. (Coulomb’s Law)

P3.7B

Explain how an object acquires an excess static charge (e.g., how your hair is affected by pulling off a wool cap, touching a Van de Graaff generator, combing it in the winter, etc.)

P3.7e

Explain why an attractive force results from bringing a charged object near a neutral object. (electrostatic induction)

P3.7c

Draw the redistribution of electric charges on a neutral object when a charged object is brought near.

P3.7d

Identify examples of induced static charges.

P3.7f

Determine the new electric force on charged objects after they touch and are then separated. (conservation of charge)

Unit 10


Unit 11

Electric Current

electric circuits

ARE EXPLAINED BY

flow of electric charges in closed circuits

ARE MEASURED BY

ARE USED TO

electric current, voltage and resistance

Big Idea Electric current is used to transfer energy and to do work.

Core Concepts •

Electric current is a flow of electric charges; the quantity of electric current (I) is the rate of flow of electric charges. Voltage (V) is the electrical force that drives a current; it is always measured between two points in a circuit. Electrical resistance (R) is a measure of an object’s opposition to a steady current. I = V/R

•

Electric power (measured in watts) is the rate at which electric energy is transferred through a circuit. Power equals current x voltage.

transfer energy

energy = power x time power = current x voltage

Inquiry, Reflection and Social Implications P1.1h Design and conduct investigations; draw conclusions Students can build simple series and parallel circuits to investigate the relationships between voltage, current and resistance. These investigations can begin qualitatively, using light bulbs to estimate quantities, then they can become more quantitative, using meters for more precise measurements (“…using appropriate tools and techniques.”) “Black box” experiments with circuits are also useful for testing their understanding. P1.1f P1.1g P1.2f P1.2g

Predict results of changes in variables Critique reasoning based on evidence Critique solutions to problems Identify tradeoffs in designs Building simple electromagnets demonstrates concepts while allowing students to investigate factors related to the magnet’s strength. Students can also build simple electric motors to understand the design solutions behind this ubiquitous technology.




P3.7g

Explain current flow in an electric circuit. (shortened)

P4.10e

Explain energy transfer in a circuit, using an electrical charge model.

P4.10C

Identify complete circuits, open circuits, and short circuits and explain the reasons for the classification. (shortened)

P4.10h

Explain how circuit breakers and fuses protect household appliances. (application)

P4.10D

Discriminate between voltage, resistance, and current as they apply to an electric circuit.

P4.10g

Compare the currents, voltages, and power in parallel and series circuits.

P4.10f

Calculate the amount of work done when a charge moves through a potential difference, V. (application)

P4.10j

Explain the difference between electric power and electric energy (as used in bills from an electric company).

P4.10i

Compare the energy used in one day by common household appliances (e.g., refrigerator, lamps, hair dryer, toaster, televisions, music players). (application)

P3.8b

Explain how the interaction of electric and magnetic forces is the basis for electric motors, generators, and the production of electromagnetic waves.

Unit 11


Unit 12

Nuclear Physics

nuclear processes involve changes in the nuclei of atoms

RADIOACTIVE DECAY

used in medical treatments and research, etc.

radioactive isotopes spontaneously decay to lighter elements

NUCLEAR FISSION

heavy nuclei like uranium split into lighter nuclei

Big Idea Radioactive decay is the spontaneous transmutation of one nucleus into another with the release of high energy particles. Nuclear fission and nuclear fusion create new elements and release high energy particles and massive amounts of radiation.

Core Concept •

Einstein’s equation E=mc2 governs the amount of energy released in nuclear reactions.

NUCLEAR FUSION

source of energy in nuclear power plants

two light nuclei like hydrogen combine to form heavier nuclei

source of sun’s energy; possible long-term energy solution

Inquiry, Reflection and Social Implications P1.2A P1.2B P1.2f

Determine scientifically answerable questions Apply science to social issues Critique solutions to problems Students can discuss important social questions like, “Are the risks worth the benefits—of nuclear energy, irradiated foods, radiation medicine, etc.”

P1.2C Access information from multiple sources P1.2g Identify tradeoffs in designs Students can discuss the many scientific trade-offs involved in nuclear power, including waste disposal. P1.2E Be aware of careers in science Students can learn about careers in the nuclear medicine, power and research fields. P1.2j Predict effects of technology P1.2k Analyze how science and society interact Students can research and discuss historical, political and social perspectives on nuclear warfare, as well as the development of theories of nuclear fission and fusion.




P4.12A

Describe peaceful technological applications of nuclear fission and radioactive decay.

P4.12B

Describe possible problems caused by exposure to prolonged radioactive decay.

P4.12C

Explain how stars, including our Sun, produce huge amounts of energy (e.g., visible, infrared, or ultraviolet light).

P4.12d

Identify the source of energy in fission and fusion nuclear reactions.

Unit 12

Also see the Chemistry HSCEs under Nuclear Stability (C2.5x) and Mass Defect (C3.5x)


P1.1 Scientific Inquiry Science is a way of understanding nature. Scientific research may begin by generating new scientific questions that can be answered through replicable scientific investigations that are logically developed and conducted systematically. Scientific conclusions and explanations result from careful analysis of empirical evidence and the use of logical reasoning. Some questions in science are addressed through indirect rather than direct observation, evaluating the consistency of new evidence with results predicted by models of natural processes. Results from investigations are communicated in reports that are scrutinized through a peer review process. P1.1A

Generate new questions that can be investigated in the laboratory or field.

P1.1B

Evaluate the uncertainties or validity of scientific conclusions using an understanding of sources of measurement error, the challenges of controlling variables, accuracy of data analysis, logic of argument, logic of experimental design, and/or the dependence on underlying assumptions.

P1.1C

Conduct scientific investigations using appropriate tools and techniques (e.g., selecting an instrument that measures the desired quantity–length, volume, weight, time interval, temperature–with the appropriate level of precision).

P1.1D

Identify patterns in data and relate them to theoretical models.

P1.1E

Describe a reason for a given conclusion using evidence from an investigation.

P1.1f

Predict what would happen if the variables, methods, or timing of an investigation were changed.

P1.1g

Based on empirical evidence, explain and critique the reasoning used to draw a scientific conclusion or explanation.

P1.1h

Design and conduct a systematic scientific investigation that tests a hypothesis. Draw conclusions from data presented in charts or tables.

P1.1i

Distinguish between scientific explanations that are regarded as current scientific consensus and the emerging questions that active researchers investigate.


P1.2 Scientific Reflection and Social Implications The integrity of the scientific process depends on scientists and citizens understanding and respecting the “Nature of Science.” Openness to new ideas, skepticism, and honesty are attributes required for good scientific practice. Scientists must use logical reasoning during investigation design, analysis, conclusion, and communication. Science can produce critical insights on societal problems from a personal and local scale to a global scale. Science both aids in the development of technology and provides tools for assessing the costs, risks, and benefits of technological systems. Scientific conclusions and arguments play a role in personal choice and public policy decisions. New technology and scientific discoveries have had a major influence in shaping human history. Science and technology continue to offer diverse and significant career opportunities.

P1.2A

Critique whether or not specific questions can be answered through scientific investigations.

P1.2B

Identify and critique arguments about personal or societal issues based on scientific evidence.

P1.2C

Develop an understanding of a scientific concept by accessing information from multiple sources. Evaluate the scientific accuracy and significance of the information.

P1.2D

Evaluate scientific explanations in a peer review process or discussion format.

P1.2E

Evaluate the future career and occupational prospects of science fields.

P1.2f

Critique solutions to problems, given criteria and scientific constraints.

P1.2g

Identify scientific tradeoffs in design decisions and choose among alternative solutions.

P1.2h

Describe the distinctions between scientific theories, laws, hypotheses, and observations.

P1.2i

Explain the progression of ideas and explanations that lead to science theories that are part of the current scientific consensus or core knowledge.

P1.2j

Apply science principles or scientific data to anticipate effects of technological design decisions.

P1.2k

Analyze how science and society interact from a historical, political, economic, or social perspective.


Changes from Companion Document: • P4.10A and P4.10B moved to Unit 1 from Unit 10 • P4.3C moved to Unit 1 from Unit 6 • P4.1B moved from Unit 12 to both Unit 7 and Unit 8 • P3.1A added to Unit 9 (not the “direct contact” part)—also appears in Unit 3 • P3.7g and P3.8b moved from Unit 9 to Unit 10 • P4.11b (Unit 1) — Original wording: Calculate the final temperature of two liquids (same or different materials) at the same or different temperatures and masses that are combined. Slightly edited: Calculate the final temperature of two liquids after they are combined, given their initial temperatures and masses (same or different materials). • P4.2C (Unit 1) — Original wording: Explain how energy is conserved in common systems (e.g., light incident on a transparent material, light incident on a leaf, mechanical energy in a collision). Slightly revised: Explain energy conservation in common systems (e.g., light incident on a leaf, mechanical energy in a collision). • P2.2D (Unit 5) — State that Explain how uniform circular motion involves acceleration without a change in speed. • P3.6d (Unit 6) — Calculate the force, masses, or distance between two bodies (added), given any three of these quantities, by applying the Law of Universal Gravitation, given the value of G. • P4.1c (Unit 7) — Original wording: Explain why work has a more precise scientific meaning than the meaning of work in everyday language. Changed to: Contrast the everyday meaning of “work” with the more precise scientific meaning. • P4.3d (Unit 7) — Original wording: Rank the amount of kinetic energy from highest to lowest of everyday examples of moving objects. Changed to: Calculate the amount of kinetic energy of everyday examples of moving objects. • P4.6A (Unit 9) — Identify the different regions on the electromagnetic spectrum and compare them in terms of wavelength, frequency, and energy. Added at end: (recognizing that all EM waves travel at the same speed in a vacuum). Rationale: This was not mentioned anywhere in the HSCEs. • P4.5C (Unit 7) Original wording: Provide evidence to support the claim that sound is energy transferred by a wave, not energy transferred by particles. Changed to: Provide evidence to support the claim that waves transfer energy, not matter. • P4.8c (Unit 7) middle phrase put in parentheses • P4.9C (Unit 8) — Original wording: Explain why the image of the Sun appears reddish at sunrise and sunset. This HSCE was generalized, with examples added in parentheses — New version: Explain how scattering accounts for atmospheric phenomena (e.g., blue sky, red sun at sunset). • P3.7B (Unit 9) — Original wording: Explain why acquiring a large excess static charge (e.g., pulling off a wool cap, touching a Van de Graaff generator, combing) affects your hair. This HSCE was generalized, with examples placed in parentheses: Explain how an object acquires an excess static charge (e.g., how your hair is affected by pulling off a wool cap, touching a Van de Graaff generator, combing it in the winter, etc.) • P3.7g (Unit 10) — Shortened: Propose a mechanism based on electric forces to Explain current flow in an electric circuit. • P4.10C (Unit 11) — Shortened: Given diagrams of many different possible connections of electric circuit elements, Identify complete circuits, open circuits, and short circuits and explain the reasons for the classification. • Some Big Ideas were reworded.

