This is an occasional activity from my childhood. Whenever my backyard would be filled with an abundance of snow I'd dive off the patio into the snow. I am curious now how much of a risk I was assuming when I did that. I didn't jump from a very high height, but I am curious now how the ability to be safely slowed to a stop by the snow; without hitting the ground underneath and  without accelerating fast enough to injure myself; relates to factors like the wetness of the snow, the snow pack, and the snow depth.

The two concepts which come immediately to my mind as important here are elasticity and compression. The compression of the snow dissipates some of the momentum with which you hit it (much like styrofoam packing peanuts in an item being shipped), and the elasticity makes the impact less rigid.

Some things can be estimated. The density of the snow, for example, indicates how much it can compress, since the max will basically be the density of ice, i.e around 0.92 g/cm^3

You don’t want to be jumping in if it’s already close to being solid ice

On 11/19/2020 at 12:14 PM, swansont said:

Some things can be estimated. The density of the snow, for example, indicates how much it can compress, since the max will basically be the density of ice, i.e around 0.92 g/cm^3

You don’t want to be jumping in if it’s already close to being solid ice

Got it, then.

 

So is there some sort of optimum density? I assume it being TOO light means it won't stop you in time to prevent you from hitting the ground. Is there some function relating density to the rate at which it slows you down?

5 minutes ago, ScienceNostalgia101 said:

 

So is there some sort of optimum density? I assume it being TOO light means it won't stop you in time to prevent you from hitting the ground. Is there some function relating density to the rate at which it slows you down?

I’m guessing there is, but I’m not sure how one would model it.

31 minutes ago, ScienceNostalgia101 said:

Got it, then.

 

So is there some sort of optimum density? I assume it being TOO light means it won't stop you in time to prevent you from hitting the ground. Is there some function relating density to the rate at which it slows you down?

I assume depth matters too. Even powdery snow should stop you eventually, and you can break through thin ice.

Believe it or not, the Russian military is alleged to have carried out tests of pilots jumping, without parachutes, into snow.

"In the early 20th century, parachute silk was rare in the Soviet Union, so the military conducted experiments with air-dropping soldiers into deep snow without parachutes.^"

From         https://en.wikipedia.org/wiki/Winged_tank

On 11/19/2020 at 4:51 PM, ScienceNostalgia101 said:

This is an occasional activity from my childhood. Whenever my backyard would be filled with an abundance of snow I'd dive off the patio into the snow. I am curious now how much of a risk I was assuming when I did that. I didn't jump from a very high height, but I am curious now how the ability to be safely slowed to a stop by the snow; without hitting the ground underneath and  without accelerating fast enough to injure myself; relates to factors like the wetness of the snow, the snow pack, and the snow depth.

I guess there are too many factors at play: compression, friction, velocity of impact, heat generated due to impact causing a little melting, depth of snow, temperature. Deducing a quantitative mathematical model is cumbersome at least.