Q: Could a water strider outrun the ripple/splash from a rock?
A: Depends on the rock.
The other day I asked myself, “Could a water strider outrun a ripple from a rock?” (I've thrown a lot of rocks at a lot of water striders.)
Doesn’t everyone?
Anyway, to answer this question, I measured the speed of ripples created by small rocks in our bathroom sink.
(Note: all rocks were dropped from about half a foot in the air unless otherwise stated.)
A water strider can reach 3.4 mph (citation: 7 Cool Facts About Water Striders – Cool Green Science. This article says striders can move at 100 body-lengths per second, which equals ~60 inches per second, which equals ~3.4 mph.)
The ripple from a piece of pea gravel travels at 2.27 mph (citation: I measured it.).
The ripple from a 2.5-inch-across piece of shale dropped on edge travels at 2.7 mph (citation: I measured it.).
The ripple from a 1.5-inch-long pebble travels at 1.4 mph (citation: I measured it.).
Then I measured a bigger rock's splash, in a river:
The ripple from a rock a little bigger than my fist travels at 3.4 mph (citation: I measured it. However, this one was thrown from 4 feet in the air).
Conclusion: a strider could easily outrun (outskip?) a ripple from a smaller rock. Larger rocks would be harder.
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