Wednesday (Day 4)

Warm-Up Wed, Mar 4 Place your homework on my desk: Calculate the electric potential at points A and B due to the charges shown. Assume V=0 at r=∞. Place your homework on my desk: Lab #4 Gaussian Grid Report For future assignments - check online at www.plutonium-239.com

Corrections to be made Essential Questions were copied but must be changed and add to top of slides Agenda was copied but needs to be changed to summation of point charges and equipotential lines with WS practice First solution slide is a guideline |<-x->| and |<-(0.52-x)->| must be added for V = 0 solution Additional slides must be modified (verify answers!!!) Correct the summary - it was copied & pasted

Essential Question(s) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? How do we calculate the electrical work done on a positive and negative charge that moves through a potential difference? How do we apply the Law of Conservation of Energy to determine the speed of a charged particle that has been accelerated through a potential difference? How do we describe and apply the concept of electric fields?

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Vocabulary Electric Potential Potential Difference in Potential Potential Difference Volt Voltage Equipotential Lines Equipotential Surfaces Electric Dipole Dipole Moment Electron Volt Cathode Ray Tube Thermionic Emission Cathode Anode Cathode Rays Oscilloscope

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Agenda Determine potential due to multiple point charges. Discuss equipotential lines Electric Fields WS #1 - 4 Equipotential WS #1 - 4 Work on Web Assign and WS

Application: Potential due to two opposite charges HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Application: Potential due to two opposite charges Calculate the electric potential at points A and B due to the charges shown. Assume V=0 at r=∞. Find the point(s) along the x-axis where V=0. Calculate the Electric Field at the point(s) along the x-axis where V=0 V=0 at (0,0)

Determination of E: Positive Point Charge HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of E: Positive Point Charge dAsphere A1 + r E

Determination of V from E: Point Charge HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Point Charge + E dr

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Important Note #1 We will now have the ability to sum up all of the point charges to determine the total potential for any charge distribution. Today is that day . . .

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Conceptual Questions If E = 0, is V = 0? Explain. In what situation can E = 0 and V ≠ 0? If V = 0, is E = 0? Explain. In what situation can V = 0 and E ≠ 0?

Application: Potential due to two charges HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Application: Potential due to two charges Calculate the electric potential at points A and B due to the charges shown. Assume V=0 at r=∞. Find the point(s) along the x-axis where V=0. Calculate the Electric Field at the point(s) along the x-axis where V=0

Application: Potential due to two charges HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Application: Potential due to two charges Calculate the electric potential at points A and B due to the charges shown. Assume V=0 at r=∞. Find the point(s) along the x-axis where V=0. Calculate the Electric Field at the point(s) along the x-axis where V=0

Application: Potential above two charges HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Application: Potential above two charges Calculate the electric potential at points A and B due to the charges shown. Assume V=0 at r=∞.

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF EQUIPOTENTIAL LINES? An equipotential is a line or surface over which the potential is constant. Electric field lines are perpendicular to equipotentials. The surface of a conductor is an equipotential. Review: Where does Vba= 0 V from rb = ∞? What is the potential difference in both cases? 10V 5V 0V -5V -10V

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF EQUIPOTENTIAL LINES? Equipotentials An equipotential surface connects points that are all at the same potential. The electric field is everywhere perpendicular to the equipotential surface.

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF EQUIPOTENTIAL LINES? Equipotentials Electric equipotential surfaces are analogous to contour lines on a topographic map (lines of constant elevation)

Equipotentials and Fields Near Conductors HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF EQUIPOTENTIAL LINES? Equipotentials and Fields Near Conductors Surface of a conductor is an equipotential Electric field is perpendicular to surface

EM Field Examples

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Summary How is the electric field lines and equipotential lines related? HW (Place in your agenda): Web Assign 23.? - 23.? Future assignments:

Thursday (Day 5)

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Warm-Up Thurs, Mar 5 How can a charge being placed in between two opposite charges have a zero potential and still have the ability to move (I.e. have a force acting on it)? Place your homework on my desk: Equipotential WS #2-4 Electric Field WS #2-4 For future assignments - check online at www.plutonium-239.com

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Equipotential Lines

Essential Question(s) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? How do we calculate the electrical work done on a positive and negative charge that moves through a potential difference? How do we apply the Law of Conservation of Energy to determine the speed of a charged particle that has been accelerated through a potential difference? How do we describe and apply the concept of electric fields?

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Vocabulary Electric Potential Potential Difference in Potential Potential Difference Volt Voltage Equipotential Lines Equipotential Surfaces Electric Dipole Dipole Moment Electron Volt Cathode Ray Tube Thermionic Emission Cathode Anode Cathode Rays Oscilloscope

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Agenda Prep Lab #5: Potential Add the conclusion question: How can a charge being placed in between two opposite charges have a zero potential and still have the ability to move (I.e. have a force acting on it)? Complete the following Lab #5: Potential Chapter 23 Web Assign Problems up to 23.6

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Summary How is the electric field lines and equipotential lines related? HW (Place in your agenda): Web Assign 23.? - 23.? Future assignments:

Friday (Day 6) In Phoenix, Arizona

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Warm-Up Fri, Mar 6 TBA Place your homework on my desk: For future assignments - check online at www.plutonium-239.com

Essential Question(s) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? How do we calculate the electrical work done on a positive and negative charge that moves through a potential difference? How do we apply the Law of Conservation of Energy to determine the speed of a charged particle that has been accelerated through a potential difference? How do we describe and apply the concept of electric fields?

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Vocabulary Electric Potential Potential Difference in Potential Potential Difference Volt Voltage Equipotential Lines Equipotential Surfaces Electric Dipole Dipole Moment Electron Volt Cathode Ray Tube Thermionic Emission Cathode Anode Cathode Rays Oscilloscope

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Agenda Complete the following Lab #5: Potential Chapter 23 Web Assign Problems up to 23.6

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Summary TBD HW (Place in your agenda): Web Assign 23.? - 23.? Future assignments: Lab #5: Potential Lab Report (Due in 5 classes)

Monday (Day 7)

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Warm-Up Mon, Mar 7 Qualitatively identify the location of the zero potential line between a positive and a negative charge? Place your homework on my desk: TBD For future assignments - check online at www.plutonium-239.com

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Equipotential Lines V = 0

Essential Question(s) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? How do we calculate the electrical work done on a positive and negative charge that moves through a potential difference? How do we apply the Law of Conservation of Energy to determine the speed of a charged particle that has been accelerated through a potential difference? How do we describe and apply the concept of electric fields?

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Vocabulary Electric Potential Potential Difference in Potential Potential Difference Volt Voltage Equipotential Lines Equipotential Surfaces Electric Dipole Dipole Moment Electron Volt Cathode Ray Tube Thermionic Emission Cathode Anode Cathode Rays Oscilloscope

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Agenda Determine V from E for A Vertical Line of Charge A Disk of Charge Concentric Sphere Graphic Organizers: Electric Field Lines and Equipotential Lines (Section 23-5) Methods for Determining E and V (23-2, 23-3, 23-4, & 23-7) Complete the following Lab #5: Potential

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Uniform Vertical Wire

E-Field: Uniformly Charged Vertical Wire (–∞+∞) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? E-Field: Uniformly Charged Vertical Wire (–∞+∞)

Determination of V from E: Uniformly Charged Vertical Wire (–∞+∞) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Uniformly Charged Vertical Wire (–∞+∞) dr

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Uniform Disk

E-Field: Uniformly Charged Disk (0R) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? E-Field: Uniformly Charged Disk (0R)

Determination of V from E: Uniformly Charged Disk (0R) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Uniformly Charged Disk (0R) dz

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL?

Concentric Conducting Spherical Shells HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Concentric Conducting Spherical Shells

Concentric Conducting Spherical Shells HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Concentric Conducting Spherical Shells – – rb E + + dAsphere – – + A1 + r1 ra + + r2 – – + + A2 – r3 – A3

Determination of V from E: Outside Concentric Spheres (r ≥ rb) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Outside Concentric Spheres (r ≥ rb) – – rb + + – – + + ra + + – – E + + – – dr Eoutside=0

Determination of V from E: Between Concentric Spheres (r  rb) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Between Concentric Spheres (r  rb) – – rb + + – – Einside=0 + + ra E + + – – + + – – dr

Determination of V from E: Between Concentric Spheres (r  ra) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Between Concentric Spheres (r  ra) – – rb + + – – Einside=0 + + ra E + + dr – – + + – –

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Between Concentric Spheres (ra< r < rb) – – rb + + – – + + ra E + + – – dr + + dr – – Eoutside=0

Determination of V from E: Center of Concentric Spheres (r < ra) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Center of Concentric Spheres (r < ra) – – rb + + – – Einside=0 + + ra dr E + + – – + + – –

Determination of V from E: Between Concentric Spheres (r  rm) HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of V from E: Between Concentric Spheres (r  rm) – – rb + + – – Einside=0 + + ra E + + rm – – + + – – dr

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Determination of rm where V = 0: Between Concentric Spheres (ra< r < rb) – – rb + + – – + + ra E + + rm – – + + – – Eoutside=0

E(r) for Concentric Spherical Shells Ea Eb r ra rm rb

V(r) for Concentric Spherical Shells Va r ra rm rb Vb

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Summary For concentric cylinders: determine V for r < ra, ra<r < rb, & r>rb determine rm in relation to ra & rb, HW (Place in your agenda): Equation for rm for concentric cylinders Future assignments: Lab #5: Potential Lab Report (Due in 5 classes) E

HOW DO WE DESCRIBE AND APPLY THE CONCEPT OF ELECTRIC POTENTIAL? Summary For concentric cylinders: determine V for r < ra, ra<r < rb, & r>rb determine rm in relation to ra & rb, HW (Place in your agenda): Equation for rm for concentric cylinders Future assignments: Lab #5: Potential Lab Report (Due in 5 classes) E

Determination of V from E: Outside Concentric Cylinders (r > rb) Einside=0 E Eoutside=0

Determination of V from E: Between Concentric Cylinders (ra<r<rb) Einside=0 E Eoutside=0

Determination of V from E: Inside Concentric Cylinders (r < ra) Eoutside=0

Determination of rm at V = 0: Between Concentric Cylinders Einside=0 E Eoutside=0