1. Charge 1Charge 2 Electric Field/Force Electric Potential and PE Misc 100 200 300 400 500 Final

2. Go back and click on a numberback (do not click the back button on your browser) continue

3. A piece of glass is charged by friction with silk. If the glass has a charge of +250 e, what is the charge of the silk? continue -250 e

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5. How do the number of protons and electrons compare in a neutral object? continue Same

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7. An object looses 8 electrons, what is its charge in elementary charges? continue +8 e

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9. DAILY DOUBLE You may wager any amount up to you current total. You have one try to answer this question correctly. An object has 3 electrons and 7 protons. What is its charge in Coulombs? 6.4 x 10 -19 C continue

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11. Electrical forces are much stronger than gravitational forces, so why don’t we typically feel electrical forces? Most objects are neutral continue

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13. Give an example of charging by friction and an example of charging by conduction. Friction – dragging feet across a carpet Conduction – getting shocked by a door knob continue

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15. Charges tend to gather at _________________. Sharp points continue

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17. ____________ are the charges that can actually move. Electrons continue

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19. Describe the difference between insulators and conductors Conductor: electrons are free to move (spread out) on the surface of the object. Insulator: electrons are stuck in one general location and are not free to move easily. continue

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21. Define the term polarization. Alignment of charges resulting in more positive charge on one side than the other continue

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23. What information can electric field lines tell you? The direction a positive test charge will move if released in the field. How close the lines are to each other show the relative strength of the electric field. continue

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25. Draw the electric field lines created by two protons near each other. continue

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27. What is the strength of the electric field at 1 m from a proton? 1.44 x 10 -9 N/C continue

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29. What is the size of the electric force on a proton in an electric field of 4.1 x 10 8 N/C? 6.6 x 10 -11 N continue

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31. What is the size of the force between a proton and an electron if they are 2.5 x 10 -5 m apart? 3.7 x 10 -19 N continue

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33. What is the potential at a location 0.1 m away from a 2 nC charge? 180 V continue

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35. What is the potential energy of a proton placed 0.1 m away from a 2 nC charge? 2.9 x 10 -17 J continue

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37. How much work is required to move a charge at a constant speed on an equipotential surface? No work is required continue + +

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39. What is the potential at point P if point A has -3 μC of charge.5 m away from P, and point B has 4 μC of charge.25 m away from P. 8.99 x 10 4 V continue A B P

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41. What is the potential energy of an electron at a point with a potential of -5.3 x 10 -10 V? 8.5 x 10 -29 J continue

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43. Explain why a person’s hair stands on end when they touch a Van de Graaff generator. The hairs all gain the same charge since charge tends to accumulate at sharp points. They repel each other and try to get as far apart as possible. continue

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45. What happens to the size of the electric force between two charges if the distance between them is tripled? 1/9 F continue

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47. A proton is moved.5 m in an electric field of 8 N/C. How much work is done on the proton? 6.4 x 10 -19 J or 4 eV continue

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49. What does it mean to say charge is conserved? You cannot gain or lose charge. i.e. Electrons and protons cannot just appear or disappear. continue

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51. Final Jeopardy You may wager any amount up to you current total. You have one try to answer this question correctly. Explain the difference between q 1 and q 2 when applied to electrostatics equations. Charge q 1 establishes the electric field. Charge q 2 experiences a force when placed inside the electric field created by q 1. continue