A Little Physics Problem, Or Jettison the Cargo and Live

This is Steven Petrick Posting.

Here is a problem in physics.

I have walked along a given stretch of sidewalk near my apartment for over 20 years, so I have covered this route something in excess of 10,000 times coming and going.

Recently I was walking from my mailbox to my apartment. I had my keys in my left hand (so I could open my apartment door) and a large diet coke in a Styrofoam cup in my right hand. The cup was full, I had not taken a drink out of it since I had left the store where I had gotten a free refill.

As my right foot came forward the bottom of the boot caught the lip of concrete between one slab and the next. Forward momentum kept me going, but now my center of gravity is ahead of where my legs are.

As you can imagine I was desperately working both legs trying to "catch" myself before I fell. I staggered four or five steps, and realized that I was "not going to make it." I was going down, so it was time to start making preparations to minimize the damage from the "crash."

I did not think it possible to veer to the left (into the grass), and veering right entailed possibly damaging other people's property (parked cars), which was fine because I do not think I had enough control at that point to veer in that direction. I was going down on the concrete and that was all there was to it.

At this juncture I began "jettisoning" anything that would interfere with minimizing the crash. I dropped my keys so that I could use the palm of my left hand instead of landing on the knuckles with the impact driving the edges of keys into my palm in addition to the possibility of fracturing my knuckles. I also disposed of the diet coke.

This is where it gets kind of weird.

The moment I jettisoned the diet coke, recovery happened. Now, this was not a case of just opening my hand to let the coke drop, I did half toss it away (holding on to it would have entailed it being destroyed on impact anyway, but my right hand's fingers would have been in an extended, and thus sub-optimal configuration for the crash landing probably resulting in dislocations if not outright fractures).

With the coke gone, there was enough shift in my center of gravity that I was able to pull myself up and, literally, short as in all forward momentum stopped before my feet entered the "debris field" of the splattered coke.

Was the weight of that coke that much of a factor in my inability to regain my balance? Or was it the weight of the coke and the impetus of thrusting it away from myself that gave me enough leeway to regain my balance?

I literally went from "crash landing is now inevitable" to "stable motion regained" as a result of jettisoning the coke.

I really do wonder, though, if it really was jettisoning the coke or some other factor I am just not aware of. All of my "built-in" systems at the point where I began preparing for the fall to the concrete were 100% certain that I was past the point of no return in regaining my balance and the fall was inevitable (or I would not have dropped the keys and the coke).

But the fall did not happen, and the recovery seemed to be entirely the result of jettisoning the coke.