Do you get wetter if you walk or run in the rain?
On a rainy day, we usually feel the urge to run to avoid getting wetter than necessary. However, the question arises as to whether this strategy would not cause even more drops to hit us, as we head towards them horizontally.
This is a classic debate in physics, and today we are going to offer you the answer. Under the rain, is it better to run or walk?
🔹 Would increasing the speed of walking make us escape from the rain or would it cause more drops to hit us instead?
The answer may disappoint you: the amount of rain that falls on you is constant, no matter how fast you go; although it does matter how long you stay in the rain and how far you walk in the rain.
To count the amount of water that falls, we have to add up the water that falls on you, plus the water that falls in front of you as you move. The amount of water falling on your area of impact is exactly the same, since that area remains constant, regardless of speed and direction.
🔹 In other words, it only matters how long you stay in the rain, but not how fast you travel a certain distance.
Running in the rainIf we stay still, the area of impact will be smaller, and less rain will fall on us. But if we are moving forward, because we have to go from point A to point B, it doesn't matter if you move faster or slower. The amount of water you're going to go through is exactly the same.
To imagine it better, let's make an analogy: every meter you advance would be like hitting a 'wall of drops'. The more meters you go, the more walls of drops you have to go through. On a journey from point A to point B, the walls of drops that you have to travel through are the same, regardless of the speed at which you travel.
But, while the speed of movement does not influence the amount of water we cross horizontally, the amount of water that falls on us per second does.
🔹 So, at the end of the day, the faster you escape the rain, the less water will hit you.
However, there are other variables to consider. Franco Bocci, a researcher at the University of Brescia (Italy), explained in the European Journal of Physics that both the direction and intensity in which the wind blows and a person's height and physical build influence the response.
According to this researcher, in most cases, the general response is to run as fast as possible. But that solution changes in the case of gusts of wind or if the person is quite thin, in which case you should not run so much. And, if the wind is blowing from behind, the optimum speed will be exactly the same as the speed of the wind.
Therefore, if you want to get as little wet as possible, it is best to make sure you run the shortest distance possible. And, if you do run, watch out for slips!