Name: ______

Week 1 - Electrostatics Day 1 – Charge Watch Edpuzzle Video: Electric Charge, Law of Charges, and Quantization of Charge Lecture Notes: https://tinyurl.com/rdmshxj

How many types of electric charge are there? What are their names?

Can an object have all of one type of charge? How can an object have a charge?

Explain when charges either attract or repel? (Law of Charges)

Explain the “Quantization” of electric charges.

What do we call an atom that has a net electric charge? How can an atom become positive? Negative?

The charge on an electron or on a proton has a magnitude of 1.6 × 10–19 C, where “C” are units of charge called “coulombs”. Of the numbers below, circle the numbers that represent amounts of charge that you CAN have.

7.0 × 10–19 C 4.0 × 10–19 C 8.8 × 10–19 C 4.8 × 10–19 C 2.4 × 10–19 C 6.4 × 10–19 C 3.2 × 10–19 C 8.0 × 10–19 C

Look this up on the Internet: What does the “Law of Conservation of Charge” say? Do not use the words “created” or “destroyed”.

Flipping Physics Lecture Notes:

Electric Charge https://www.flippingphysics.com/charge.html

The Law of Charges: • Like charges repel & • Unlike charges attract

When we rub fur against a rubber rod and then a rubber balloon, electrons transfer from the fur to the rubber objects leaving the rubber objects with a net negative charge and the fur with a net positive charge. When we rub silk against a glass rod, electrons transfer from the glass rod to the silk leaving the glass rod with a net positive charge and the silk with a net negative charge.

Electrons and Protons are very, very tiny particles with charge magnitude equal to e: • e = 1.60 x 10-19 coulombs, C • e = elementary charge • e = smallest charge measured on an isolated particle. • Coulombs, C = SI unit for charge • Charge on electron = -e & Charge on proton = +e m = 9.11×10−31 kg & m =1.67 ×10−27 kg • electron proton m 1.67 ×10−27 kg proton = ≈1830 m 9.11×10−31 • A proton is much more massive than an electron. electron kg • electron = elementary particle • proton is not an elementary particle because it is composed of quarks.

Quarks are elementary particles which make up protons and neutrons: 2 1 & qupquark = + e qdownquark = − e • 3 3 ⎛ 2 ⎞ ⎛ 1 ⎞ 4 1 q = 2q +1q = 2 + e + − e = + e − e = +e proton up quark down quark ⎜ 3 ⎟ ⎜ 3 ⎟ 3 3 • ⎝ ⎠ ⎝ ⎠ ⎛ 2 ⎞ ⎛ 1 ⎞ 2 2 q =1q + 2q = + e + 2 − e = + e − e = 0 neutron up quark down quark ⎜ 3 ⎟ ⎜ 3 ⎟ 3 3 • ⎝ ⎠ ⎝ ⎠

When you take a rubber balloon and rub it against fur, three things are possible. 1) The balloon will stay in your hair. a. Rub rubber balloon against hair and electrons transfer from hair to balloon. b. Balloon now has a net negative charge and hair now has a net positive charge. c. Law of Charges: unlike charges attract. d. Electric force pulls hair and balloon together. 2) Pull the balloon away from your hair and some of your hairs will stick out. a. Rub rubber balloon against hair and electrons transfer from hair to balloon. b. Hair now has a net positive charge. c. Law of Charges: like charges repel. d. • Electric force pushes hair apart.

0336 Lecture Notes - Electric Charge.docx page 1 of 2 3) The balloon will stick to a wall. a. This is polarization which we will learn about in a future lesson. i. https://www.flippingphysics.com/polarization.html

−19 The elementary charge is very small: e =1.60 ×10 C = 0.000000000000000000160C

Example: How many excess protons does it take to get a charge of 1 coulomb on an object? For this we need a new equation: q = ne • q = net charge on an object • n = excess number of charge carriers • e = elementary charge q 1C q = ne ⇒ n = = = 6.25 ×1018 protons e 19 C 1.60 ×10− proton q = 6.25 quintillion protons = 6.25 million million million protons = 6,250,000,000,000,000,000 protons

Example: Can an object have a net negative charge of 2.00 times 10 to the negative 19 coulombs?

q −2.00 ×10−19C q = ne ⇒ n = = =1.25electrons e 19 C −1.60 ×10− electron

However, you cannot have a quarter of an electron because charge is quantized. • Charge comes in discrete quantities in multiples of the elementary charge. • Charge is caused by having more or fewer charged particles (protons or electrons). • The charge on an object, q, must be an integer multiple of the elementary charge, e. • In q = ne , n, the number of charge carriers, has to be an integer. • Because you cannot cut protons and electrons into pieces.

−19 So the answer is … No, you cannot have a net charge of −2.00 ×10 C on an object.

0336 Lecture Notes - Electric Charge.docx page 2 of 2 Day 2 - Coulombs Law

1.) First watch this Edpuzzle video and answer the questions. Links are below.

Edpuzzle Video: https://tinyurl.com/sczga28 Lecture Notes: https://tinyurl.com/ump4xve

2.) Go to Physics Classroom Interactive: https://tinyurl.com/yaj523wk Define Radius: How is it measured? Draw a diagram:

2a) Change in Radius: Instructions: Click on the ruler to move it towards the center of your grid. • Place your charges 10 units away from each other as shown below

• Place your masses so that they are 5 units apart. You’re able to move charges by clicking on them and sliding them into place.

• Place your masses 2.5 units away from each other.

Record your Forces here. Radius Charge q1 Charge q2 Force Fq1 on q2 10 units 50x10^-6 600x10^-6 3N 5 units 50x10^-6 600x10^-6 2.5 units 50x10^-6 600x10^-6

What type of relationship is there between Force and Radius?

Which experiment trials should be used to determine the relationship between force and distance? Fill in the table below with those experiment trials. What type of relationship is there between force and charge 1? Teacher Example: Experiment Distance r Force Fq1 on q2 1 1 1 8 2 1/4 9 3 1/9 10 4 1/16 a.) Why do you think it was important for us to choose experiments 1, 8, 9, and 10 to compare Force and Radius?

b.) Why is it not a good option to choose experiments 2 through 7?

c.) Which experiment trials should be used to determine the relationship between force and charge 1? Fill in the table below with those experiment trials. What type of relationship is there between force and charge 1?

Experiment Charge q1 Force Fq1 on q2

d.) Which experiment trials should be used to determine the relationship between force and charge 2? Fill in the table below with those experiment trials. What type of relationship is there between force and charge 1?

Experiment Charge q2 Force Fq1 on q2

e.) What is Coulomb’s Law? State as words and an equation. Draw a diagram. Explain what k is.

Quiz on Charge, and Coulombs law

Day 3 - Polarization 1.) Polarization Edpuzzle: https://tinyurl.com/vdug38p Lecture Notes: https://tinyurl.com/yx8ehlej Polarization Interactive Physics classroom: https://tinyurl.com/ybntwfjx

Day 4 Charging Conduction & Induction Conduction & Induction Edpuzzle https://tinyurl.com/w4hxfrv Lecture Notes: https://tinyurl.com/yxxa62et Tutorial Induction: https://tinyurl.com/y63hn9s3 Tutorial Conduction: https://tinyurl.com/vhd54ox

Day 5 – Conservation of Charge & Charging by Friction

1.) Conservation of Charge edpuzzle: https://tinyurl.com/v8dbdyh Physics Classroom tutorial Triboelectric charging (Charging by friction): https://tinyurl.com/yxre9kv4

a.)

b.)

c.)

Test your Understanding Week 1 Quiz