1. Day 59 End of Topic 7! Starting Topic 8.

2. What’s Due and When: HW Turn In: Next Class, ◦ HW: Titled Day 54, Day 57, Day 59. ◦ So the HW is due Formal Lab: Checked with partners today, ◦ In my hands: Next Class (6) Miniquiz: Next class

3. Today: Last Day of Topic 7/First of Topic 8 1 st bit of time: Finishing lab/confirming with partners Goal One: To begin to understand a new physics idea that deals with Charges.

4. 1 st : Lab Talk For about 10 minutes, with partners make sure you are all going to be ready to base your grade off each other. I will take questions…

7. So a bunch of new ideas are coming your way that still deal with charges

8. Current In the wire at every point, a bunch of charge is flowing every moment. Current is the Flow of Charge through a conductor

9. GIVE THIS ½ A PAGE. 18 LINES NEEDED Label every 2 lines…1 to 6. The last 4 lines will be Equations section

10. GIVE THIS ½ A PAGE. 18 LINES NEEDED

11. Example One: 3x10 14 electrons are pushed every minute through a wire. How much current is that?

12. Example Two: You Try A person has 400 milliamps go though their heart to start it up. It took 3 seconds, how much charge flowed?

13. Voltage A field creates a force in the wire. Its like a difference in Potential (like a push) on the ends of the wire push charge through. Charge flows from High Potential to Low Potential. A difference in Potential causes currents to flow. Back to the chart…

14. Resistance Different wires can have different flows There are 4 different properties that affect the resistance. More resistance with the same potential difference means LESS current Back to the chart…

15. River Analogy Electric IdeaRiver Example

17. Ohms Law The relationship between Electric Potential, Resistance and Current

18. Example Three: A metal wire is connected between two battery leads. In an hour, 3 coulumbs flowed. If the wire is 75 ohms, A) How much electric potential is there on the wire?

19. Example Three: A metal wire is connected between two battery leads. In an hour, 3 coulumbs flowed. If the wire is 75 ohms, B) If the high lead is 3 volts, what is the low?

20. Example Four: Which of the following changes to a wire will always bring about an increase in current? A) Increase voltage and increase resistance B) Decrease voltage and decrease resistance C) Increase voltage and decrease resistance D) Decrease voltage and increase resistance

21. Example Four: Which of the following changes to a wire could bring about an increase in current? A) Increase voltage and increase resistance B) Decrease voltage and decrease resistance C) Increase voltage and decrease resistance D) Decrease voltage and increase resistance

22. Example Five: You Try An outlet has two prongs, + (120 volts) and – (0 volts). You place a 20 Ω wire from the + prong to a 30 volt battery. The battery charges in 20 minutes. How much charge flowed?

23. And Now… Try it out on the HW