By the end of this unit, a successful student will be able to:
- Understand the concept of electric charge so they can:
- Describe the types of charge and the attraction and repulsion of charges (APCIIIA1a1) (20.1, 20.2)
- Describe polarization and induced charges (APCIIIA1a2) (20.2)
- Recognize that an electric charge tends to be static on insulators and can move on and in conductors, and explain that energy can produce a separation of charges. (MSTE:Phys 5.1) 20.1
- Understand Coulomb’s Law and the principle of superposition so they can
- Calculate the magnitude and direction of the force on a positive or negative charge due to other specified point charges. (MSTE: Phys 5.4; APCIIIA1b1) (20.2)
- Analyze the motion of a particle of specified charge and mass under the influence of an electrostatic force (APCIIIA1b2) (20.2)
- Students should understand induced charge and electrostatic shielding, so they can:
- Describe the process of charging by induction. (APCIIIB1c1) (20.2)
- Explain why a neutral conductor is attracted to a charged object. (APCIIIB1c2) (20.2)
- Understand the concept of electric field so they can:
- Define it in terms of the force on a test charge (APCIIIA2a1) (21.1)
- Describe and calculate the electric field of a single point charge (APCIIIA2a2) (21.1)
- Calculate the magnitude and direction of the electric field produced by two or more point charges (APCIIIA2a3) (21.1)
- Calculate the magnitude and direction of the force on a positive or negative charge placed in a specified field. (APCIIIA2a4) (21.1)
- Interpret an electric field diagram (APCIIIA2a5) (21.1)
- Analyze the motion of a particle of specified charge and mass in a uniform electric field (APCIIIA2a6) (21.1)
- Understand the concept of electric potential so they can:
- Determine the electric potential in the vicinity of one or more point charges (APCIIIA2b1) (21.2)
- Calculate the electrical work done on a charge or use conservation of energy to determine the speed of a charge that moves through a specified potential difference (APCIIIA2b2) (21.2)
- Determine the direction and approximate magnitude of the electric field at various positions given a sketch of equipotentials (APCIIIA2b3) (21.2)
- Calculate the potential difference between two points in a uniform electric field and state which point is at the higher potential (APCIIIA2b4) (21.2)
- Calculate how much work is required to move a test charge from one location to another in the field of fixed point charges (APCIIIA2b5) (21.2)
- Calculate the electrostatic potential energy of a system of two or more point charges, and calculate how much work is required to establish the charge system (APCIIIA2b6) (21.2)
- Students should understand the nature of electric fields in and around conductors, so they can:
- Explain the mechanics responsible for the absence of electric field inside a conductor, and know that all excess charge must reside on the surface of the conductor. (APCIIIB1a1) (21.2)
- Explain why a conductor must be an equipotential, and apply this principle in analyzing what happens when conductors are connected by wires. (APCIIIB1a2) (21.2)
- Students should be able to describe and sketch a graph of the electric field and potential inside and outside a charged conducting sphere. (APCIIIB1b) (21.1, 21.2)
- Understand the definition and function of capacitance, so they can:
- Relate stored charge and voltage for a capacitor. (APCIIIB2a1) (21.2)
- Relate voltage, charge, and stored energy for a capacitor. (APCIIIB2a2) (21.2
- Recognize situations in which energy stored in a capacitor is converted to other forms. (APCIIIB2a3) (21.2)
- Understand the physics of the parallel-plate capacitor, so they can:
- Describe the electric field inside the capacitor, and relate the strength of this field to the potential difference between the plates and the plate separation. (APCIIIB2b1) (21.2
- Determine how changes in dimension will affect the value of the capacitance. (APCIIIB2b4) (21.2)
- Use mathematical representations Coulomb’s Law to describe and predict the electrostatic forces between objects (NGSS PS2-4)
- Create a computational model to calculate the change in the energy of one component in a system when the change (NGSS PS3-1)
- Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as either motions of particles or energy stored in fields. (NGSS PS3-2)
All assignments are due on the date listed. That is not the date they are assigned.
(2013 due dates)
Due date Day Assignment
1/2 Wed- Project Presentations
1/4 Fri Project Presentations – project papers due.
1/7 Mon Read: 20
Do: pp. 421-422 RC: 1, 4, 5
AC: 2, 5, 8, 12
1/11 Fri Do pp. 422-423: 2, 4,11,14,15,17,18,19
1/14 Mon Read: 21
Do: pp. 443-444 RC: 1, 4, 9, 10, 13
AC: 3, 7, 8, 9
1/17 Thu Do: pp. 444-445: 4, 5, 7, 9, 11,12, 16,17,19, 22
1/17 Thu Test 20, 21
1/21 Mon Martin Luther King Jr. Day – No School
1/22 Tue Ohm’s Law lab
1/24 Thu Final Exam
1/25 Fri Make-up Day
1/28 Mon AP Physics begins
- Electricity and magnetism had known of to one degree or another since ancient times. The Greeks recorded that the rubbing of amber with wool caused that wool to be attracted to the amber as far back as 600 BCE.
- Prentice Hall's web page on Giancoli Chapter 16 Electric Charge and Electric Field.
- Haliday, Resnick and Walker's page on Chapter 22 - Electric Charge (Calculus based)
- Haliday, Resnick and Walker's page on Chapter 23 - Electric Fields (Calculus based)
- Prentice Hall's web page on Giancoli Chapter 17 Electric Potential and Electric Energy; Capacitance
- Haliday, Resnick and Walker's page on Chapter 25 - Electric Potential (Calculus based)
- Haliday, Resnick and Walker's page on Chapter 26 - Capacitance (Calculus based)
- William Gilbert (1544-1603), physician to Queen Elizabeth published one of the earliest scientific studies on magnetism De Magnete. He also studied and classified a number of materials that were capable of holding electrostatic charges when rubbed - testing more than the traditional amber and jet. This page is a brief biography from the Galileo Project.
- Otto von Guericke is most famous for demonstrating the forces resulting from atmospheric pressure by creating a partial vacuum within the Magdeburg sphere and failing to uncouple the hemispheres, even with teams of horses, before air was returned to the interior of the sphere. He's also credited with developing what may be the first electrostatic generator in 1672, which operated by spining a ball of sulfer against a pad.
- Charles Du Fay (1698-1739) is credited with being the first to classify electrical charge into two fluids: the resinous (which resulted from rubbing substances like amber) and the vitreous (which resulted from rubbing substances like glass) and noting that like fluids repeled, while opposing fluids attracted.
- Pieter van Musschenbroek at the University of Leyden in the Netherlands invented a way to store electrical charge in 1745 in a device which became known as the Leyden Jar. These devices were the first capacitors, and an array of them, just like an array of artilery, became known as a battery.
- The Bizarre Leyden Jar page explains how to construct your own Leyden jar. As does this Leyden jar page.
- Twyla Kitts's Leyden Jar page descibes an elementary and middle school level lab for making the devices with pie plates.
- In the 1780's Charles Augustin de Coulomb performed experiments with the torsion pendulum which enabled him to calculate the strength of the electrostatic force. Coulomb's experimental design was copied by Henry Cavendish for his "weighing of the Earth" experiment, which determined the size of the gravitational constant "G" from Newton's law of universal gravitation. This page was written by J.J. O'Connor & E F Robinson.
- Another page on Coulomb can be found here.
- Between 1799 and 1800, Count Alessandro Volta (1745-1827)invented the voltaic pile, essentially a series of capacitors, which was the forerunner of the modern electric battery. Another article on Volta can be found at The Catholic Encyclopedia, with yet another at The Idea Factory