Lesson 8 (Gravitation and Orbits) of Dianna's Intro Physics Class on Physics Girl. Never taken physics before? Want to learn the basics of physics? Need an AP Physics 1 review before the exam? This course is for you! Exercises in this video: 1. An object with mass M is a distance R from the center of the earth. Another object with mass 2M is at a distance 3R from the center of the earth. What is the ratio of the forces between each object and the earth? 2. What is the force of gravity between the Earth and a pineapple with mass of 1kg, if the pineapple is falling near the Earth’s surface? 3. What would the acceleration due to gravity be on a planet with half the radius, but twice the mass of Earth? 4. The ISS orbits with an average altitude of 410 km. What is its orbital velocity? What is its orbital period? 5. Extras Credit: What is the orbital velocity of an object orbiting the Earth at a height of 35,800 km above the Earth’s equator? (Don’t forget to add in the Earth’s radius!). What is the orbital period? Credits: Dianna Cowern - Executive Producer/Host/Writer Jeff Brock - Lead Writer/Course Designer Laura Chernikoff - Producer Victoria C. Page - 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