Lesson 15 (Angular Momentum) 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! More fun exploration of water spinning angular momentum demo from Steve Mould and Smarter Every Day: https://www.youtube.com/watch?v=M4-L8UgPkOk Exercises in this video: 1. A box and a sphere are sliding and rolling, respectively, down a ramp. If they start from the same height, and we ignore friction on the box, which will reach the ground first? What if it were a full soda can and an empty soda can? 2. A sphere of mass 4kg rolls down a ramp, starting with a height of 5 meters from the ground. How fast is the sphere rolling when it gets to the ground? 3. If every person on Earth ran around the equator in the same direction, what would their total angular momentum be? Use 65 kg as the average mass of the 7.8 billion people on Earth, and let them run at 5m/s. 4. Given 8 x 10³⁷ kg•m² as the Moment of Inertia of Earth, by how much would all those people running change the angular speed of the Earth? Special thanks to Kari Byron for her wonderful shoutout at the end of the video! You can follow her on Twitter @KariByron and Instagram @therealkaribyron. Credits: Dianna Cowern - Executive Producer/Host/Writer Jeff Brock - Lead Writer/Course Designer Laura Chernikoff - Producer Kaitlyn Today - Video Editor 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