Uploaded January 2021 | Updated September 2026, 2 weeks ago

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Lesson 18 (Electric Charge and Light) of Dianna's Intro Physics Class on Physics Girl. Never taken physics before? Want to learn the basics of physics? Need a review of AP Physics concepts before the exam? This course is for you!

Exercises in this video:
1. How many electrons are in 1 Coulomb of charge? How many protons?

2. What is the electromagnetic force between an electron and a proton that are separated by 1nm?

3. To compare, what would the force of gravity between the proton and the electron be?

4. An electron is in a constant electric field with a strength of -4.4x10^5N/C. What force is being exerted on that electron by the field?

Credits:
Dianna Cowern - Executive Producer/Host/Writer
Jeff Brock - Lead Writer/Course Designer
Laura Chernikoff - Producer
Kaitlyn Ali - Video Editor
Bryn Bishop - AP Curriculum Consultant
Sophia Chen - Researcher/Writer
Erika K. Carlson - Researcher/Writer
Hope Butner - Production Assistant
Levi Butner - Videographer
Lauren Ivy - Set Design
Vanessa Hill - Consulting Producer
Aleeza McCant - Illustrator
Rachel Allen - Illustrator
Consultant - Kyle Kitzmiller
Lucy Brock, Samantha Ward - Curriculum Consultants
Cathy Cowern - Transcription