4 upvotes, 3 direct replies (showing 3)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
Do you actually get rained on less if you run through it?
It probably has something to do with the amount of area you cover, because I always feel like it doesn’t make any difference. The faster you go, the faster you encounter more water?
Comment by Anti_Markovnikov at 26/04/2023 at 21:39 UTC
3 upvotes, 0 direct replies
Mythbusters tried to answer this. https://youtu.be/HtbJbi6Sswg
Comment by cosmicosmo4 at 27/04/2023 at 04:39 UTC
1 upvotes, 0 direct replies
Imagine yourself as a rectangular block. Let's assume rain is falling straight down. If you travel to your destination at infinite speed, then the amount of rain that hits you is going to be equal to the frontal area of your blocky self, multiplied by the distance of travel, multiplied by the amount of rain per square meter in the air. In this example, because we traveled at infinite speed, the rain is considered to be motionless. We move so fast that no rain hits the *top* of the block.
If you go any slower than that, then the amount of rain that hits the front of the block is exactly the same, but some rain will also hit the top of the block. That amount is equal to the area of the top of the block times the average downward speed of the rain, multiplied by the amount of rain per square meter in the air (same as above), multiplied by the time it takes to reach the destination. That latter term obviously increases if you go slower.
So, in the simplest case, running faster doesn't change how wet the front of your body gets, but it reduces how wet the top of your head gets. If you add some wind, or change the shape of the person to something other than a rectangular block, then things get a little more complicated.
Comment by TanteTara at 27/04/2023 at 09:09 UTC
1 upvotes, 0 direct replies
If you move a certain distance through a constant rainfall, the water hitting your front will be the same for every speed. Imagine the raindrops in the crossed volume as stationary to visualize this.
However, the rain accumulating on your top surface will be more the slower you go, because it only depends on the time you spend in the rain.