What is a force ? Is gravity a "real" force ? And what is the origin of contact forces ? All these answers in 14 minutes ! 0:00 - Introduction 2:00 - Inertial forces 4:12 - Gravity 7:57 - Contact forces 8:56 - Fundamental interactions 11:52 - Conclusion For more videos, subscribe to the YouTube channel : null And if you liked this video, you can share it on social networks ! To support me on Patreon : http://www.patreon.com/ScienceClic or on Tipeee : http://tipeee.com/ScienceClic Facebook Page : http://facebook.com/ScienceClic Twitter : http://twitter.com/ScienceClic Instagram : http://instagram.com/ScienceClic Alessandro Roussel, For more info: http://www.alessandroroussel.com/en _ To learn more : https://en.wikipedia.org/wiki/Force