1. Friday(03/05): Introduction to Ch.22, covering single-loop circuits,

Ohm's Law, and schematic diagrams of simple circuits. HW: Read and

Study pages 591-600, then solve problems 65, 66, 67, and 68 on

page 611.

2. Monday(03/08): LAB on Ohm's Law. HW: Process lab data and write

lab report, due Friday.

3. Tuesday(03/09): Report to 1^st period. Testers report to testing

location. Non-testers (gym or see below).

·        Extended time testers will complete only first session of Reading.

·        AP Micro students report to the cafeteria.

·        Testing should conclude by 12:50pm.

4. Wednesday(03/10): Report to 1^st period. Testers report to testing

location. Non-testers (gym or see below).

FCAT Math, g.9, g.10, & Retakes; FCAT Rdg, Ext. Time Testers;        

·        FCAT Sci. Pract., g.11.

·        AP Gov. students report to the cafeteria.

·        Extended time testers will complete only second session of Rdg.

5. Thursday(03/11): Report to 1^st period. Testers report to testing

location. Non-testers (gym or see below).

·        Report to 1^st per. class; then, ESE and ESOL students report to their extended

         time testing locations for the second session of the Reading FCAT.

         Grade 11 students report to testing locations for the FCAT Science test.

         changes have been made) report to former testing location from 3/09 and 3/10

         for an extended time. 

6. Friday(03/12): Review of the concepts of single-loop electric circuits.

HW: Read and Study pages 601-609, then solve problems 71, 72, 73, and

74 on page 612.

7. Monday(03/15): Continue with study of electric circuits, power,

energy, and schematic diagrams of series and parallel circuits.

HW: Solve problems 82, 83, 84, and 85 on pages 612-13.

8. Tuesday(03/16): Review of all electric circuits. HW: Read and

Study pages 617-26, then solve problems 58, 59, 60, and 61 on

page 637.

9. Wednesday(03/17): Combination circuits (series and parallel

together).  HW: Read and Study pages 627-35 then solve problems

73, 74, 75, and 76 on page 638.

10. Thursday(03/18): LAB on Series Circuits. HW: Process data.

Lab report, due Monday.

11. Friday(03/19): Review I for Ch.22&23. HW: Complete Review

Handout.

12. Monday(03/22): Review II for Ch.22&23. HW: Complete Review

Handout.

13. Tuesday(03/23): TEST on Ch.22 & 23. HW: Go to website and

study notes for Ch.24 - Magnetic Fields.

1. In electricity two fundamental concepts are current and voltage. For

any electrical element the voltage (V) across the element is the potential

difference between its two ends, while the current, I, through the element

is the rate at which electrical charges are flowing.

2. For many devices (but not all) the voltage and the current are

proportional to each other, and we can write V = I·R in which R is a

constant of proportionality known as the resistance.

3. The equation, V = I·R is known as Ohm's Law, and devices which obey

Ohm's Law are known as linear or ohmic devices.

4. Familiar examples are resistors which are found in radios, TV sets,

computers, and other electronic systems; the filaments of light bulbs; and

the heating elements of electrical ovens.

5. There are however other devices which do not obey Ohm's Law,

semiconductor devices such as transistors and diodes, and fluorescent

light bulbs. These are known as nonlinear devices.

6. Ohm's Law can be used to solve simple circuits. A complete circuit is one

which is a closed loop. It contains at least one source of voltage

(thus providing an increase in potential energy) and at least one potential

drop, i.e. a place where potential energy decreases.

7. If a potential difference (voltage) is maintained across a resistor, the

power, can be calculated with P = VI = I²R = V²/R.

8. Since energy is the ability to do work, and work is power x time, we also

have W = E = Pt = VIt = I²Rt = V²t/R. We usually measure this in kWh,

the kilo-Watt-hour with 1 kWh = 3.6x10⁶ J. The cost is ~ $.12 from the

power company.

9. Because of the electrostatic force, which tries to move a positive charge

from a higher to a lower potential, there must be another 'force' to move

charge from a lower potential to a higher inside the battery.

10. This so-called force is called the electromotive force, or emf. The SI unit

for the emf is a volt (and thus this is not really a force, despite its name).

We will use a script E, to represent the emf.

11. A decrease of potential energy can occur by various means. For example,

heat lost in a circuit due to some electrical resistance could be one source of

energy drop.

12. For resistors in series, use simple addition: R_EQ = R₁ + R₂ + … + R_n .

For resistors in parallel, use reciprocals: 1/R_EQ = 1/R₁ + 1/R₂ + … + 1/R_n .

19. And still, we need these steps to solve any problem in Physics:

(i) read the problem and identify the given variables

(ii) determine what you are asked to solve for

(iii) find the correct motion formula to use

(iv) use algebra to isolate the unknown

(v) substitute-in the given information and simplify.

Answers to Homework:

Page 611: #65. 960 W, #66. 140 W, #67. 60 W, 1.8x10⁴ J, #68. 2500 J/s, 2500 W

Page 612: #71. 24 V, #72. 6.0 V, #73. 120, #74. 5.0 A, #82. $510/kWh

Page 613: #83. .15 A, #84. 1.2x10⁶ J, #85. $216

Page 637: #58. 12 kΩ, #59. .40 kΩ, #60. 12.4 V, #61. 4.45 A

Page 638: #73. 8.89 Ω, 4.50 A, 2.50 A, #74. 66 Ω, #75. 160 Ω, #76. 52 Ω, 110 V, 9.8 Ω, 96 V

THE HONORS PHYSICS ARCHIVES Ch.1: Physics Intro. Ch.2&3: Linear Motion. Ch.4&5: Forces. Ch.6: 2-Dim Motion. Ch.7: Gravitation. Ch.8: Rotary Motion. Ch.9: Momentum. Ch.10&11: Work&Energy. Ch.12: Thermal Energy. Ch.13: States of Matter. Semester Review. Ch.14&15: Waves&Sound. Ch.16: Study of Light. Ch.17&18: Reflect/Refract. Ch.19: Int/Diffraction. Ch.20&21: Electrostatics