The physics of why ducklings swim in a row behind their mother.
via Science News
Earlier measurements of duckling metabolism showed that the youngsters saved energy when swimming behind a leader, but the physics behind that savings wasn’t known. Using computer simulations of waterfowl waves, naval architect Zhiming Yuan of the University of Strathclyde in Glasgow, Scotland, and colleagues calculated that a duckling cruising in just the right spot behind its mother gets an assist.
When a duckling swims on its own, it kicks up waves in its wake, using up some energy that would otherwise send it surging ahead. That wave drag resists the duckling’s motion. But ducklings in the sweet spot experience 158 percent less wave drag than when swimming alone, the researchers calculated, meaning the duckling gets a push instead.
Source: https://blog.adafruit.com/2021/10/24/why-do-ducklings-swim-in-a-row/