1. (Mon) Electrostatic force depends on the amount of charge on the ions and the distance between the charges. Which change would have a bigger affect – doubling the charge (2x) or shortening the distance ½? Why did you pick this change (use the equation to help explain your answer) (8 min / 10 pts)

2. Shortening the distance by ½ Why:F = kq 1 q 2 /r² Starting Values F = k(1)(1)/(1)² F = k(1) For 2x the charge F = k(2)(1)/(1)² F = k(2) For ½ the distance F = k(1)(1)/(½ )² F = k(4)

3. (Tue) A negative ion with a charge of -1 sees two positive ions: one with a charge of +1 and another with a charge of +2. If the ions are all 1 m apart, which one will the negative ion be more strongly attracted to? Using the force equation, explain why it would be attracted to one more than the other. (5 min / 8 pts)

4. (Tue) A negative ion with a charge of -1 sees two positive ions: one with a charge of +1 and another with a charge of +2. If the ions are all 1 m apart, which one will the negative ion be more strongly attracted to? Using the force equation, explain why it would be attracted to one more than the other (5 min/8 pts) Attracted to the +2 Ion Why: F = kq 1 q 2 /r² +1+2 For the left one: F = k(1)(1)/(1)² F = k(1) For the right one: F = k(2)(1)/(1)² F = k(2)

5. (Wed) The picture below shows 4 ions with the amount of charge shown on each ion. Which two ions will have the smallest repelling force between them? Explain why you chose those ions (5 min / 8 pts)

6. Which two? Ion #1 and Ion #2 Why these? 2. F = kq 1 q 2 /r² 4. 1-2 are farther apart than 3-4 so have less force 1. Alike Repel 3. 1-2 and 3-4 Both have same amount of charge so same amount of force due to the charge

7. (Thu) How did the transistor help to make electronic devices smaller? What are the two uses for a transistor in today’s electronics? (5 min / 6 pts)

8. How? Transistors replaced larger vacuum tubes in many electronic devices 2 Uses: Control large current with a small current (Amplifier) Electronic Switch (Computer)

9. (Fri) A positive and a negative ion (+1 and -1 charge) are next to each other. If they are initially 1 m apart and then are moved to 3 meters apart, how does the force between the ions change (gets bigger / smaller)? Using the force formula, how much does the force between the ions change? (10 min / 10 pts)

10. How changes?Force goes down (gets smaller) How much? Initially: F = kq 1 q 2 /r² F = k(1)(1)/(1)² F = k(1) After moving: F = kq 1 q 2 /r² F = k(1)(1)/(3)² F = k(1/9) How much change? Final force is 1/9 th the size of the original

11. End of Week Procedures 1.Add up all the points you got this week 2.Put the total number of points out of 42 points you earned at the top of your page (no total, lose 5 points) 3.List any dates you were absent or tardy (and why) 4.Make sure your name and period # is on the top of the page (no name, no credit) 5.Turn in your papers