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Notes : Electricity and Magnetism

Notes : Electricity and Magnetism. How do you produce Electricity ?. DRIVING QUESTION !. FOCUSED LEARNING TARGET. Given different materials , I will be able to explain conductivity by induction and polarization.

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Notes : Electricity and Magnetism

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  1. Notes : Electricity and Magnetism

  2. How do you produce Electricity ? DRIVING QUESTION !

  3. FOCUSED LEARNING TARGET • Given different materials , I will be able to explain conductivity by induction and polarization. • Given different elements , I will be able to review , how a material is charged using the Periodic Table. • Given metals and non metals , I will be able to test that electron charges flow and create potential difference or voltage using potatoes and lemons . • Given charges and the distance between these particles, I will be able to calculate the Electric Force Fe = k q1q2 / r2

  4. Electric Fence Experiment. Can you guess what will happen? ELECTRICITY What would life be like without electricity? Talk with your group List 4 things that you would miss the most:            1) ______________________________           2) ______________________________           3) ______________________________           4)______________________________           

  5. Draw a balloon ! Where are the electrons in a balloon ? Gray/Black

  6. Review Chemistry P 254 Conceptual Physics

  7. Review Chemistry

  8. REVIEW CHEMISTRY : USE PERIODIC TABLE PAGE 254 4 Positive (Metal) Ion and 4 Negative(Non Metal) IONS – 60 points Choose a Partner . Share and Learn as A Team by Explaining Verbally and Listening ONLY. NO COPYING directly from Paper = O creditWork Your element -5 min; Share your element 2 minutes; Listen for another element 2 minutes

  9. METALS Sodium Potassium Calcium Magnesium Barium Beryllium Copper Barium Zinc NON METALS Oxygen Bromine Nitrogen Sulfur Fluorine Neon Carbon Helium Hydrogen

  10. Use Red Marker Where are the electrons ?Based on the lesson : Atomic Structure

  11. What happened to the electrons ? Based from the experiment “ Balloon Attraction “? – Green Marker

  12. Balloon VS HairBalloon VS Bits of Paper Take a Photo of the Event Explain the Phenomena In 1 paragraph. Use your phone , to explain what happened .

  13. Different materials have different amounts of attraction for electrons.   When two objects rub against each other it is likely that one will steal electrons from the other.  (see triboelectricity)    If you rub a balloon against your hair, the balloon will steal electrons from your hair. This leaves your hair positively charged and the balloon negatively charged.   Your hair will be attracted to the surface of the balloon because opposite charges attract.  You will also notice that your hair stands up even if the balloon is not near them.  This is because each hair is positively charged and is repelled by the hair next to it.  The forces between similarly charged hair causes them to try and get as far away from each other as possible.  CHARGING A BALLOON WITH YOUR HAIR

  14. You should also notice that after rubbing the balloon on your hair, you can get the side of your balloon that touched your hair to stick to other things like a wall or ceiling.  This happens because the negative charge on the balloon will force some of the electrons in the wall to move to the other side of their atoms.  This leaves the surface of the wall closest to the balloon positively charged.  The positive surface of the wall and the negative surface of the balloon will attract each other.  If the air is very dry, the balloon should stick for many hours, possibly even days!  Remember, that the moisture in the air can steal charges from the balloon, so on humid days this may not work at all.  (see the lesson on charge theft) http://www.regentsprep.org/Regents/physics/phys03/aeleclab/ballrub.htm CHARGING A BALLOON WITH YOUR HAIR

  15. Read the Charging A Balloon Article What really happened to the electrons ? Blue marker

  16. Behavior: 50 pts Safety , Participation ,Focus Organization and Cleanliness TITLE & Subtitle – 10 pts I. Purpose – 10 pts II. Materials – 10 pts III. Background Information. 20 pts Discuss at least 2 concepts (2 paragraphs minimum) IV. Diagram Set up Drawing–Labeled- 10 pts V. Procedures-10 pts VI. Analysis and Conclusion 20 VII. Photos -10 pts Laboratory Experiment Short ReportFormat-150 pts

  17. Positive and Negative Charge • atoms have protons (positive) and electrons (negative);  neutrons are neutral • when objects have an excess of electrons, they become negatively charged Opposites attract Objects with the same charge repel

  18. 32.6Charging by Induction • Induced - Excess negative charge has moved to the other sphere, leaving the first sphere with an excess positive charge. • The charge on the spheres • has been redistributed, • or induced.

  19. Diagram of an Atom Protons and Neutrons are in the center Electrons orbit around the outside       -- these are SUBatomic particles Bohr model of the atom Label the protons, neutrons, electrons, and the nucleus

  20. Static electricity occurs when electrons transfer to your clothes or hair and give them a charge.  When you touch something, the charge is released, causing a "jolt" Each hair is negatively charged and repels other hairs. Or balloons stick to the cat

  21. Balloon VS HairBalloon VS Bits of Paper Take a Photo of the Event Explain the Phenomena In 1 paragraph.

  22. 32.6Charging by Induction • Induced - Excess negative charge has moved to the other sphere, leaving the first sphere with an excess positive charge. • The charge on the spheres • has been redistributed, • or induced.

  23. Positive and Negative Charge • atoms have protons (positive) and electrons (negative);  neutrons are neutral • when objects have an excess of electrons, they become negatively charged Opposites attract Objects with the same charge repel

  24. Electric fields surround every charge and can act upon other objects (even without touching them)The force created by this field can either                          attract          or           repel

  25. Choose your topic among the 4 topics : Electrical Force and Charges Conservation of Charge Coulomb’s Law Conductors and Insulators ELECTRICITY Notes p 500– 20 minutesRead- Notes (5 minutes), thenShare – 1 minute eachGroup of 4

  26. What is an Electric Force ? Can it be calculated ? What are the factors affecting electric force ?

  27. 19. Coulomb’s law states that for charged particles or objects that are small compared with the distance between them, the force between the charges varies directly as the product of the charges and inversely as the square of the distance between them. 32.3Coulomb’s Law

  28. 32.3Coulomb’s Law Recall from Newton’s law of gravitation that the gravitational force between two objects of mass m1 and mass m2 is proportional to the product of the masses and inversely proportional to the square of the distance d between them:

  29. Force, Charges, and Distance 32.3Coulomb’s Law The electrical force between any two objects obeys a similar inverse-square relationship with distance. The relationship among electrical force, charges, and distance—Coulomb’s law—was discovered by the French physicist Charles Coulomb in the eighteenth century.

  30. 32.3Coulomb’s Law For charged objects, the force between the charges varies directly as the product of the charges and inversely as the square of the distance between them. 20.Where: d is the distance between the charged particles. q1 represents the quantity of charge of one particle. q2 is the quantity of charge of the other particle. k is the proportionality constant.

  31. Electric Charge – The specifics Some important constants: • The symbol for CHARGE is “q” • The unit is the COULOMB(C), named after Charles Coulomb • If we are talking about a SINGLE charged particle such as 1 electron or 1 proton we are referring to an ELEMENTARY charge and often use, e , to symbolize this.

  32. 32.3Coulomb’s Law The SI unit of charge is the coulomb, abbreviated C. 21. A charge of 1 C is the charge of 6.24 × 1018 electrons. A coulomb represents the amount of charge that passes through a common 100-W light bulb in about one second.

  33. The Electrical Proportionality Constant 32.3Coulomb’s Law The proportionality constant k in Coulomb’s law is similar to G in Newton’s law of gravitation. 22. k = 9,000,000,000 N·m2/C2 or 9.0 × 109 N·m2/C2 If a pair of charges of 1 C each were 1 m apart, the force of repulsion between the two charges would be 9 billion newtons. That would be more than 10 times the weight of a battleship!

  34. 32.3Coulomb’s Law Newton’s law of gravitation for masses is similar to Coulomb’s law for electric charges. Whereas the gravitational force of attraction between a pair of one-kilogram masses is extremely small, the electrical force between a pair of one-coulomb charges is extremely large. The greatest difference between gravitation and electrical forces is that gravity only attracts but electrical forces may attract or repel.

  35. Coulomb’s law Computational Example p 507

  36. #29/ 540 College Physics An electron and proton are separated by 2nm. What is the magnitude of the force of the electron ? #33/540 College Physics Two point charges of -2.0uC are fixed at the opposite ends of the meterstick. Calculate the electric force between them. Coulomb’s Law Practice Problem

  37. Read Chapter 15 : College Physics P 513 – 539 Ex 15. 3 P 523

  38. CW : Coulomb’s Law College Physics p 540 #29

  39. FOCUSED LEARNING TARGET • Given different materials , I will be able to explain conductivity by induction and polarization. • Given different elements , I will be able to review , how a material is charged using the Periodic Table. • Given metals and non metals , I will be able to test that electron charges flow and create potential difference or voltage using potatoes and lemons . • Given charges and the distance between these particles, I will be able to calculate the Electric Force Fe = k q1q2 / r2

  40. What are Good Conductors of electricity ?

  41. Conductor - material in which electrons can flow freelyEx. Metals, such as copperInsulator - electrons do not move easily throughEx. plastic, rubber

  42. 24. Elements ELEMENTS METALS NON METALS METALLOIDS

  43. gR Groupings of Elements Elements are classified as metals, nonmetals, or metalloids based on their properties. Metals are shiny and conduct heat and electric current. Nonmetals are dull in appearance and do not conduct heat or electric current. Metalloids have properties of both metals and nonmetals.

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