Aug 26, 2011
My Life, As Physics Problem
Posted in: Miscellaneous
The Tech ran an article about our site redesign / admissions wiki today. Amita Gupta, a freshman member of the inaugural Tech FPOP, interviewed Matt and I yesterday for it, and the article is pretty awesome, so go read it!
Some of you may have read my blog post about my bike accident.
In it, I talked about how my internal dialogue immediately after my accident was all about trying to figure out the physics of my crash and how that might have affected the fact that I escaped mostly unharmed.
The problem is I haven't taken physics in like six years, and besides F=MA and watching my teacher set his hair on fire I don't remember many of the specifics. So I emailed Yan '12, who is also President of MIT Undergraduate Women in Physics, and asked her to do some physics for me.
Here's what she emailed back:
So sometimes when I'm modeling the physics of real-life scenarios, it's useful to start with the absolute simplest scenario that may or may not answer all the interesting questions about what's going on. Let's call this "Level 0."
At Level 0, it's pretty easy to explain what happened. I'm going to assume that (1) only the component of the car's velocity along your line of travel (make this the y-axis) affects your probability of survival and (2) the relative y-velocity between you and the car is related to the force along y delivered to your bike in some simple way (for instance, linearly).
Say that the car is traveling at 35 MPH. Its y-velocity is then 35/sqrt(2) MPH, or around 25 MPH. If you're traveling at 20 MPH along y and collide with the car, the situation is the same as if you collided with a stationary car while biking at 5 MPH. As opposed to if the car had been traveling directly at you or from the side, in which case you would have collided with it at significantly higher velocities (55 MPH and 35 MPH, respectively).
Hope this helps!
It does help, Yan. It does help. It helps me confirm what I had already thought to be true: that angular velocity saved my life.
p.s. a blogging brownie to whomever in the comments can come up with the best illustrations for the various scenarios described by Yan above. I'll edit any into the body of the text.