When iOS 7 came out, the animations were the first thing everyone noticed. Some people even claimed they got seasick watching their phones. Now we know why: those flat, pastel-coloured cards can hit nearly 27km/h as they zip toward your face.
Over at Buzzfeed, John Herrman and Jake Levy looked at some of the physics behind iOS 7 animations. When you open a homescreen app and it zooms in to fill your screen, it's moving toward you from an imaginary start point 1.6m away. Since the animation takes 0.8 seconds, that calculates out to 7.2km/h. Jogging speed.
Opening apps from a folder really puts the pedal to the metal. Thanks to perspective, the tiny app icons inside a folder look like they're 5.9m away. Zooming in on a folder takes 0.8 seconds, meaning that folder flies toward your face at an average speed of 26.4km/h. But since the icon speeds up in the middle of its trip and slows down toward the end, Buzzfeed estimates its top speed at over 32.2km/h. That's like driving down a city street!