https://www.nsf.gov/news/special_reports/football/index.jsp
https://science360.gov/obj/video/.../science-nfl-football-newtons-third-law-motion
https://phet.colorado.edu/
http://www.walter-fendt.de/ph14e/
IB Physics Guide 2016.pdfIGCSE-329750-2019-syllabus.pdfIB Physics Guide 2016.pdfIGCSE-329750-2019-syllabus.pdf