1. Day 64 Topic 8: Charges and Circuits Electric Power, Costs and More

2. 3 rd Quarter Last HW: Do For Next Class (65) along with this one (65). 2 Things Due! Considered covered Next Class: Classwork occuring, MiniQuiz! 2 More New Learning Days Left (Lab on 66) Q3 Review Day 67 3/25, 3/26 Q3 Exam Day 68 3/27, 3/30 Brunch of Champions Day 69 3/31, 4/1

3. My Goals: 1. The 4 things that affect resistance: Knowing and applying 2. Using Power to find energy and costs

4. First Of All…You Do 20 bulbs (each one is 20 ohms) are connected so each has a potential difference of 30 v. A) How much power do the bulbs give off?

5. First Of All…I Do 20 bulbs (each one is 20 ohms) are connected so each has a potential difference of 30 v. B) In 10 minutes, how many joules are given off?

6. Power and Resistance In order to explore power, we now need to discover the 4 things that affect resistance. Grab a RESISTOR from me

7. With the wire in your hand… What physical things about that wire can you change to make a different amount of flow occur?

8. The 4 things: Think of cars… Length: Thickness: Material: Temp:

9. Ohmic Vs Non-Ohmic If a situation is Ohmic, the resistance will not change if the voltage or current changes (i.e. temp don’t matter). V=IR works If a situation is Non-Ohmic, then the resistance changes with different voltages or currents. Temp plays a role

10. Which one/ones are Ohmic? Which one/ones show that the resistance is increasing?

11. Part Two: Energy From our tables, Power is Energy/Time. Energy symbol is:measured in To the table:

12. Lets try…

13. And You…