Weight loss. If your cat is overweight, you will want to feed for 2 pounds less, or 40 fewer calories a day, and readjust every time your cat loses a pound, until you hit a healthy weight, and then maintain.  Differences in metabolism.
Since the speed of sound through the standard atmosphere is 761 mph (1,223 km/h) at sea level, Mach 2 then follows as 1,522 mph (2,447 km/h). If you were to ask how fast is Mach 2 at an altitude of 30,000 ft (9,150 m), we would use the same methodology to find out that it is only 1,356 mph (2,180 km/h) because the speed of sound generally decreases as altitude increases.
Let's skip Machs 3-19 and go to Korosensei's max speed, Mach 20. Well, to find this speed er need to get 343*20 which is 6,860 M/ Per Sec, or 23 thousand km/ per hour. To put that into perspective, the moon is 384 thousand kilometres away. The world's fastest rocket is 7.9 kilometres per second.