Revision as of 17:48, 28 August 2025

 🌐 Version en français : Électrostatique

 
   ⬅ Back to Electricity & Magnetism

General Resources

📖 Reference Textbook:
University Physics Volume 2: Chapter 5 – Electrostatics

Theory

⚡ Charge, Conductors, and Insulators

Electric Charge (q)

Basic property: Objects can have a positive or negative charge.
Types: Positive (more protons than electrons), Negative (more electrons than protons).
Conservation: Charge is neither created nor destroyed, only transferred.
Quantized: $Q = n \cdot e$ , with $e = 1.6 \times 1 0^{- 19} C$ .

Conductors

Charges move freely.
Examples: copper, silver, salt solutions.

Insulators

Charges can’t move freely.
Examples: glass, rubber, plastic.

⚖️ Coulomb’s Law (Scalar Form)

The magnitude of the electrostatic force $F_{t s}$ between two point charges $q_{s}$ (source charge) and $q_{t}$ (test charge), separated by a distance $r$ , is: $F_{t s} = k \cdot \frac{| q_{s} | \cdot | q_{t} |}{r^{2}}$ , with $k \approx 8.99 \times 1 0^{9} N \cdot m^{2} / C^{2}$ .

➡️ Coulomb’s Law (Vector Form)

$\vec{F_{t s}} = k_{e} \frac{q_{s} q_{t}}{r^{2}} \hat{r}$

Where:

$\vec{F_{t s}}$ = force on test charge
$k_{e} \approx 8.99 \times 1 0^{9} N m^{2} / C^{2}$
$q_{s}, q_{t}$ = charges
$r$ = distance
$\hat{r}$ = unit vector from source to test charge

📝 Example Calculations

✋ Triboelectric Effect

When two materials rub and separate, electrons transfer → one becomes negative, the other positive.

Higher in series (glass, hair) → lose electrons → positive
Lower (rubber, Teflon) → gain electrons → negative

Daily life examples: balloon on hair; static cling in clothes.

Demonstrations

💧 Bending Water

🎈 Balloon on a Wall

⚙️ Simulations

 
   ⬅ Back to Electricity & Magnetism

 
   Next: The Electric Field ➡

@@ Line 1: / Line 1: @@
-Back to [[Electricity_and_Magnetism]]
+<!-- Top-right link to FR version -->
-<div style="float:right; font-size:90%;">
+<div style="float:right; font-size:90%; margin:0.25em 0 0.75em 0;">
-[[/Électrostatique|🌐 Version en français : Électrostatique]]
+  [[/Électrostatique|🌐 Version en français : Électrostatique]]
 </div>
-= Textbook =
+<!-- Top Back button (no background box) -->
-[https://openstax.org/books/university-physics-volume-2/pages/5-introduction University Physics Volume 2: Chapter 5]
+<div style="margin:0.25em 0 0.75em 0; overflow:auto;">
+  <span style="float:left; border:1px solid #0ea5e9; background:transparent; padding:0.4em 0.8em; border-radius:6px; box-shadow:none; font-weight:600;">
+    [[Electricity_and_Magnetism|⬅ Back to Electricity & Magnetism]]
+  </span>
+</div>
+<br style="clear:both;" />
+== General Resources ==
+<div style="border: 1px solid #28a745; padding: 0.8em; background-color: #f0fdf4; margin: 1em 0;">
+  <p><strong>📖 Reference Textbook:</strong><br>
+  [https://openstax.org/books/university-physics-volume-2/pages/5-introduction University Physics Volume 2: Chapter 5 – Electrostatics]</p>
+</div>
+----
 = Theory =
-== Charge, Conductors, and Insulators: Introduction to Electrostatics ==
+== ⚡ Charge, Conductors, and Insulators ==
 === Electric Charge (q) ===
-* '''A basic property''': Objects can have a positive or negative electric charge.
+* '''Basic property''': Objects can have a positive or negative charge.
-* '''Types''': Positive charge (more protons than electrons), Negative charge (more electrons than protons).
+* '''Types''': Positive (more protons than electrons), Negative (more electrons than protons).
 * '''Conservation''': Charge is neither created nor destroyed, only transferred.
-* '''Quantized''': <math> Q = n \cdot e </math>. Charge exists in multiples of the '''elementary charge''' <math> e = 1.6 \times 10^{-19} \, \text{C} </math>.
+* '''Quantized''': <math> Q = n \cdot e </math>, with <math> e = 1.6 \times 10^{-19} \,\text{C} </math>.
 === Conductors ===
-* '''Definition''': Materials where electric charges (electrons or ions) can move freely.
+* Charges move freely.
-* '''Examples''': Metals like copper and silver. Salt-Solutions.
+* Examples: copper, silver, salt solutions.
 === Insulators ===
-* '''Definition''': Materials where charges can’t move freely.
+* Charges can’t move freely.
-* '''Examples''': Glass, rubber, and plastic.
+* Examples: glass, rubber, plastic.
 <youtube>-Oq16ndKja8</youtube>
 <br class="clear"/>
-== Coulomb's Law without vectors ==
+----
-The magnitude of the electrostatic force <math> F_\mathrm{ts} </math> between two point charges <math> q_\mathrm{s} </math> (source charge) and <math> q_\mathrm{t} </math> (test charge), separated by a distance <math> r </math>, is given by:
-<math> F_\mathrm{ts} = k \cdot \frac{|q_\mathrm{s}| \cdot |q_\mathrm{t}|}{r^2} </math>
+== ⚖️ Coulomb’s Law (Scalar Form) ==
-where <math> k \approx 8.99 \cdot 10^9~\mathrm{N \cdot m^2 / C^2} </math> is the electrostatic constant.
+The magnitude of the electrostatic force <math> F_\mathrm{ts} </math> between two point charges <math> q_\mathrm{s} </math> (source charge) and <math> q_\mathrm{t} </math> (test charge), separated by a distance <math> r </math>, is:
+<math> F_\mathrm{ts} = k \cdot \frac{|q_\mathrm{s}| \cdot |q_\mathrm{t}|}{r^2} </math>,
+with <math> k \approx 8.99 \times 10^9 \,\mathrm{N \cdot m^2 / C^2} </math>.
 <youtube>8grMx_6xl18</youtube>
+----
-== Coulomb's Law in Vector Form ==
+== ➡️ Coulomb’s Law (Vector Form) ==
-The electrostatic force, as a vector, <math> \vec{F_{ts}} </math> between two point charges <math> q_s </math> (source charge) and <math> q_t </math> (test charge), separated by a distance <math> r </math>, is given by:
 <math> \vec{F_{ts}} = k_e \frac{q_s q_t}{r^2} \hat{r} </math>
-where:
+Where:
-* <math> \vec{F_{ts}} </math>: Force (vector) on the test charge by the source charge
+* <math> \vec{F_{ts}} </math> = force on test charge
-* <math> k_e </math>: Electrostatic constant, approximately <math> 8.99 \times 10^9 \, \text{N m}^2/\text{C}^2 </math>
+* <math> k_e \approx 8.99 \times 10^9 \, \mathrm{N\,m^2/C^2} </math>
-* <math> q_s </math>: Source charge (the charge exerting the force)
+* <math> q_s, q_t </math> = charges
-* <math> q_t </math>: Test charge (the charge the force is exerted on)
+* <math> r </math> = distance
-* <math> r </math>: Distance between the charges
+* <math> \hat{r} </math> = unit vector from source to test charge
-* <math> \hat{r} </math>: Unit vector (a vector of length one) pointing from the source charge to the test charge
 <youtube>MwzwnhxoQh4</youtube>
 <br class="clear"/>
-=== Calculation Example of Coulomb's Law in Vector Form ===
+=== 📝 Example Calculations ===
 <youtube>7oYnrb89gmk</youtube>
 <youtube>VmPTG-jRaF0</youtube>
 <br class="clear"/>
-== Triboelectric effect/series or triboelectricity ==
+----
-The '''triboelectric effect''' is a phenomenon where certain materials become electrically charged after they come into contact and are then separated. This effect occurs due to friction, causing electrons to transfer between the materials. As a result, one material gains electrons (becoming negatively charged) and the other loses electrons (becoming positively charged).
-Different materials have varying tendencies to gain or lose electrons, which are organized in the '''triboelectric series'''. Materials higher on the series (such as glass or hair) tend to lose electrons and become positively charged, while materials lower on the series (such as rubber or Teflon) tend to gain electrons and become negatively charged.
+== ✋ Triboelectric Effect ==
+When two materials rub and separate, electrons transfer → one becomes negative, the other positive.
-The triboelectric effect is commonly observed in everyday life, for example:
+* Higher in series (glass, hair) → lose electrons → positive
-* When a balloon rubbed on hair makes the hair stand up.
+* Lower (rubber, Teflon) → gain electrons → negative
-* When synthetic clothing generates static cling.
+Daily life examples: balloon on hair; static cling in clothes.
 <youtube>Fph08eKTVZM</youtube>
 <br class="clear"/>
+----
 = Demonstrations =
-== Bending Water ==
+=== 💧 Bending Water ===
 <youtube>u-SIJSSBsjo</youtube>
-<br class="clear"/>
-== Sticking a balloon to the wall ==
+=== 🎈 Balloon on a Wall ===
 <youtube>bjU-Ll6U1ig</youtube>
 <br class="clear"/>
+----
-= Electrostatics Simulations =
+= ⚙️ Simulations =
-Check out these links for playing with charges:
+* [http://phet.colorado.edu/en/simulation/travoltage PhET: Be careful, John Travolta!]
+* [http://phet.colorado.edu/en/simulation/balloons PhET: Charge up a balloon]
+* [http://www.thephysicsteacher.ie/lcphysics19staticelectricity.html The Physics Teacher: Static Electricity resources]
+* [http://regentsprep.org/regents/physics/phys03/alightnin/ Lightning applet]
-*[http://phet.colorado.edu/en/simulation/travoltage Be careful John Travolta!] <br>
+<!-- Bottom Back and Next buttons -->
+<div style="margin:1.25em 0 0.5em 0; overflow:auto;">
+  <!-- Back button -->
+  <span style="float:left; border:1px solid #0ea5e9; background:#fff; padding:0.4em 0.8em; border-radius:6px; box-shadow:0 1px 2px rgba(0,0,0,0.12); font-weight:600;">
+    [[Electricity_and_Magnetism|⬅ Back to Electricity & Magnetism]]
+  </span>
-*[http://phet.colorado.edu/en/simulation/balloons Charge up a balloon] <br>
+  <!-- Next button -->
+  <span style="float:right; border:1px solid #10b981; background:#fff; padding:0.4em 0.8em; border-radius:6px; box-shadow:0 1px 2px rgba(0,0,0,0.12); font-weight:600;">
-These and more links can be found at:
+    [[The Electric Field|Next: The Electric Field ➡]]
+  </span>
-<!--http://www.thephysicsteacher.ie/lcphysicsstaticelectricity.html<br>-->
+</div>
-http://www.thephysicsteacher.ie/lcphysics19staticelectricity.html<br>
-<!--http://www.regentsprep.org/Regents/physics/phys03/aeleclab/default.htm<br><br>-->
-See how lightning strikes:
-[http://regentsprep.org/regents/physics/phys03/alightnin/ Lightning applet]<br><br>
-<br class="clear"/>
-Back to [[Electricity_and_Magnetism]]<br class="clear"/>
-Next: [[The Electric Field]]

Electrostatics: Difference between revisions

Revision as of 17:48, 28 August 2025

Contents

General Resources

Theory

⚡ Charge, Conductors, and Insulators

Electric Charge (q)

Conductors

Insulators

⚖️ Coulomb’s Law (Scalar Form)

➡️ Coulomb’s Law (Vector Form)

📝 Example Calculations

✋ Triboelectric Effect

Demonstrations

💧 Bending Water

🎈 Balloon on a Wall

⚙️ Simulations

Navigation menu

Electrostatics: Difference between revisions

Revision as of 17:48, 28 August 2025

General Resources

Theory

⚡ Charge, Conductors, and Insulators

Electric Charge (q)

Conductors

Insulators

⚖️ Coulomb’s Law (Scalar Form)

➡️ Coulomb’s Law (Vector Form)

📝 Example Calculations

✋ Triboelectric Effect

Demonstrations

💧 Bending Water

🎈 Balloon on a Wall

⚙️ Simulations

Navigation menu

Search