Free Fall | Physics Explained 3.3

On the Moon in 1971, a hammer and a feather hit the ground at the same instant. This lesson explores the acceleration due to gravity: what g = 9.80 m/s² means, how to get its sign right, how g differs on other worlds, and what G-forces are. Then a full worked example, a rock thrown straight up from a cliff, with its position, velocity and acceleration graphs, and the famous trap: the acceleration at the top of the flight is not zero. Chapters: 0:00 Intro 1:02 The acceleration due to gravity 1:58 Getting the sign right 2:45 G-forces 3:58 Worked example: a rock off a cliff 5:23 The graphs of a throw 6:12 The trap at the top 7:08 Recap 7:56 Check yourself 9:05 Up next Physics Explained, Chapter 3: Acceleration (lesson 3 of 3) Adapted from Physics by OpenStax (https://openstax.org/details/books/ph..., licensed under CC BY 4.0 (https://creativecommons.org/licenses/.... The animations and narration are original to Prime Mover. OpenStax is not affiliated with this channel and does not endorse it. Prime Mover: learn it, build it, share it.