SortStack #295 — 2027-03-31

By speed · Order from slowest to fastest.

1. The growth of human hair 175.3 mm/year

   Scalp hair grows roughly 1.25 centimetres a month, so a single strand reaching your shoulders is years old.

2. A three-toed sloth 240 m/h

   Sloths move so slowly that algae grows in their fur, giving them a greenish camouflage in the canopy.

3. A racing greyhound 76 km/h

   Greyhounds reach their top speed in just a few strides and spend much of a sprint completely airborne.

4. A running pronghorn antelope 97 km/h

   The pronghorn can run far faster than any predator alive today, likely escaping a cheetah that went extinct in America.

5. A helicopter at top speed 290 km/h

   A helicopter's top speed is capped because the blade tips would approach the sound barrier and lose lift.

6. A bullet from a .357 Magnum 1.5K km/h

   A supersonic bullet creates a tiny sonic boom, which is part of the sharp crack you hear from a gunshot.

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