page9 Published September 29, 2018 at 1024 × 768 in 9/24 – 9/28/18 (Cir.Mot.;Duets) PhyFl18SS1.7.3 Sheet 1.7.7 You can think about any type of linear motion on the surface of the earth as if it were circular motion since the world is a big ball. just like the ant crawling around the basketball.