1. Coulomb’s Law
Week 2.2

2. Short Week! This Week Today – Coulomb/Electric Field(?)
Friday – Quiz #1 + More of Wednesday
Short Week!

3. Good Table Physics
Y Y Y Y
Y N N N

4. Rubbings

5. Simulations There are two kinds of simulations Software
Hardware – “Mission Space”
Software –
Software
Games – Madden Game
Training – Military at RDECOM/STRICOM
Education – The Electric Hockey Game

6. Hardware Simulation

7. Electric Hockey Sumulation
The “Game” aspect
Allowed you to get a feel for how charged particles move under the influence of coulomb forces.
Did you notice any “orbits”??
The “Measurement” aspect
Simulator incorporates accurate model of coulomb forces.
You can “explore” how these forces behave and get a feel for how they vary with distance.

8. Coulomb’s Law Simulation
Force r

9. Last Time My Data Distance (r) Force 2.0 32.5 2.8 16.0 3.0 11.7 3.8
8.0
4.8
5.5
3.3
6.7
2.3
1.6
9.0
1.3
10.3
0.8
11.3
0.7

10. Graph - Linear

11. A Little Algebra:

12. Ln-Ln
Straight Line

13. In the figure, three charged particles lie on a straight line and are separated by a distance d. Charges q1 and q2 are held fixed. Charge q3 is free to move but happens to be in equilibrium (no net electrostatic force acts on it).
OBSERVATIONS
The force from q1 is the same as the force from q2.
The charge on q1 is must be bigger than the force on q2
The two charged must be OPPOSITE in sign.

15. In the basic CsCl (cesium chloride) crystal structure, Cs+ ions form the corners of a cube and a Cl- ion is at the cube's center (See Figure). The edge length of the cube is 0.4 nm. The Cs+ ions are each deficient by one electron (and thus each has a charge of +e), and the Cl- ion has one excess electron (and thus has a charge of -e).
What is the magnitude of the net electrostatic force exerted on the Cl- ion by the eight Cs+ ions at the corners of the cube?

16. Three point charges have equal magnitudes, two being positive and one negative. These charges are fixed to the corners of an equilateral triangle, as the drawing shows. The magnitude of each of the charges is 5.0 µC, and the lengths of the sides of the triangle are 5.0 cm. Calculate the magnitude and direction that charge B experiences.

17. Back to Work! Begin on page -8- of Unit 02 Finish at Home
We Start Unit 03
on Friday