1. Electrostatics - Tape Lab

2. Tape lab (pt. 1) Make a tape “Flag”
Make a top (T1) and bottom (B1) tape sandwich
Make another pair of top and bottom tapes (T2 & B2)
Directions
Hang T1 and B1 off the end of the table. (see figure below)
Bring T2 near T1, note what happens.
Bring B2 near T1, note what happens.
Rip off a strip of paper, bring it near T1 & B1, note what happens.
Layer tapes like so… T1 B1

3. Tape lab (pt. 2) Remove old flags from the table
Make a top (T1), Middle (M1), and bottom (B1) tape sandwich
Make another set of top, middle, and bottom tapes (T2, M2, & B2)
Directions
Hang T1, M1, and B1 off the end of the table. (see figure below)
Bring T2, M2, and B2 close to each, note what happens.
Bring a strip of paper close to each, note what happens.
Answer questions at the bottom with your group.
Layer tapes like so… T1 M1 B1

4. Questions Q1: Which particles in the atom are charged?
Protons
Neutrons
Electrons
Protons & electrons
All
none
Q1: Which particles in the atom are charged?
Q2 : Electricity is due to the movement of which particle?

5. Tape behavior Attract Repel Do nothing
____________________ charge ____________________ charges ____________________ charges

6. What is a charge? An imbalance of positive and negative charges
e-excess =
E-deficiency =
E- in balance =

7. Different methods of charging
Friction
Rubbing 2 objects together.
Electrons move from one object to another
Objects get opposite charges
Conduction
Touching a charged object to a neutral one.
Objects get the same charge.

8. Different methods of charging Cont…
polarization
When charged is brought close to (but not touching!) neutral.
Grounding **ADD to notes**
The removal of charge from an object

9. Charging by friction (details)
One object always positive.
While the other object always negative.

10. Charging by conduction
Need two conductors
When you get zapped by a doorknob, this is called charging by lightning.

11. Charging by polarization

12. Scientific notation + exponent: large # - exponent: small #
Ex1) 8.5 x 106 * 9.9 x 105 = __________________
Ex2) x 105 * 2.50 x 10-6 = _________________

13. CALCULATING CHARGE The unit of charge (q) is the coulomb. FORMULA:
Ex3) An object has 1x1021 electrons taken away from it. What is the charge?

14. CALCULATING CHARGE The unit of charge (q) is the coulomb. FORMULA:
Ex4) An object has an excess of 5 x 1020 electrons. What is the charge on it?

15. Conducting spheres Take the math average:
Ex5) What charge results from these spheres being touched?
+3C , -1C
+10C , -12C
+6C , -6C
0C , +8C
0C , 0C

16. Shocking and electric fields
Getting Shocked:
There will only be a shock if there is a difference in charge.
Electric Fields:
Everything that has a charge has an electric field around it.
Electric Field Diagrams:
Charges are drawn out of the positive and into the negative.

17. Current But…electricity doesn’t flow through all objects equally!
How difficult it is to get electricity to flow through something =
__________________________________________________________________
Conductor –
Insulator –

18. Example
Example: 9V Battery
On Finger On Tongue

19. Can your cell phone cause a fire at a gas station?
Your answers: _____ Yes ______No
Real Answer:

20. How does lightning work?
Electricity likes to jump into things that are:
Metals (conductors)
Tallest point
Pointy shape
That’s why lightning rods are placed
on the highest point of a building &
grounded.

21. But Really, How does lightning work?
1. Cloud : Charged by friction (-)
3. Lightning bolt: Evening out the charge
2. Earth’s Surface gets polarized

22. Lightning safety
How many people die in the USA yearly from lightning strikes?

23. Look at the stats. Lightning's no joke.

24. Don’t hide under a tree... Liquid water becomes super- heated steam…
Tree explodes.

25. It’s safe in your house...just
Don’t become part of the house circuit…
Don’t
Use a corded device
Shower/bathe
Stay away from windows and doors

26. Also safe in your car… NOT due to the rubber tires!
Inside a hollow metal shell, no electricity flows.
(Faraday Cage)