https://www.youtube.com/watch?v=qu_P4lbmV_I&list=PL0_bz-agtdg4BVLE1_iCU5f_vXQM0fJB_&index=8       Newtons second Law Football

https://www.youtube.com/watch?v=xy3xLTeWgpg&index=12&list=PL0_bz-agtdg4BVLE1_iCU5f_vXQM0fJB_     Dr Skateboard