W5D3 POTENTIAL & MORE POTENTIAL

1. There is still one unidentified clicker. Whoever this is will not be receiving any clicker points. W5D3 POTENTIAL & MORE POTENTIAL

2. PLEASE TURN IN PART I OF THE WORKSHEET Let’s Discuss the last Worksheet Electric Potential I. Work and Potential Difference

3. A Work and Potential Difference • An object travels from point A to point B while two constant forces of equal magnitude, and , are exerted on it. Think about the work done by each force and the net work. • Is the work done on the object by F1positive, negative, or zero? • A Positive • B Negative • C Zero • D More information is needed B

4. A Work and Potential Difference • An object travels from point A to point B while two constant forces of equal magnitude, and , are exerted on it. Think about the work done by each force and the net work. • Is the work done on the object by F2positive, negative, or zero? • A Positive • B Negative • C Zero • D More information is needed B

5. A Work and Potential Difference • An object travels from point A to point B while two constant forces of equal magnitude, and , are exerted on it. Think about the work done by each force and the net work. • Is the work done on the object by the net force positive, negative, or zero? • A Positive • B Negative • C Zero • D More information is needed B

6. A Work and Potential Difference • An object travels from point A to point B while two constant forces of equal magnitude, and , are exerted on it. Think about the work done by each force and the net work. • Is the magnitude of the velocity of the object at point B greater than, less than, or equal to the velocity of the object at point A? Explain how you can tell. • A Positive • B Negative • C Zero • D More information is needed B

7. A Work and Potential Difference • An object travels from point A to point B while two constant forces of equal magnitude, and , are exerted on it. Think about the work done by each force and the net work. • Which, if any, of your responses to questions 1, 2, 3, or 4 would change if the magnitude of F1was twice as great as the magnitude of F2? B

8. Quick Summary • If the net force on an object is zero but it is moving from Point A to Point B, it is in equilibrium and is moving at constant velocity. • If the net force on this object is NOT zero, then it is accelerating and gaining energy (Kinetic). • In the absence of any other forces, the net work done by these forces is equal to the change in kinetic energy + the change in potential energy. • REMEBER: PE=qV • UNITS OF V is VOLTS. (Big surprise).

9. Klick

10. Consider the following: DEFINITION +Q D -Q UNIFORM ELECTRIC FIELD E Area = A s=Q/A A Capacitor is a device like the above that STORES CHARGE. There is a potential difference between these two plates. (V) The capacitance C is equal to the charge/potential difference. C=Q/V Q=CV

11. Consider the following: +Q D -Q UNIFORM ELECTRIC FIELD E Area = A s=Q/A Work needed to move unit charge from A to B also is (magnitude, anyway) FxD=ED (unit charge)

12. So .. What does it all mean?? The capacitance of a parallel plate capacitor depends only on geometrical factors. NOT on charge or potential difference! Interesting?? Resistors and Inductors Do The Same Thing.

13. Moving charges in a capacitor while they are in equilibrium HUH?? Ms. Field Mr. External

14. WORKSHEETS – Electric Potential Part II & then Part III & maybe Part IV or V