When I find myself stuck in traffic, my mind first turns to the shortcomings of public transit for my typical commute - a part of me wishes I still lived downtown. The next place my mind often wanders to is physics; a surprising number of seemingly abstract scenarios actually describe the motion (or lack thereof) of one's car in a system of interconnected streets.
One such analogy is that of a system of interconnected springs and masses:
Imagine that you are the sixth car waiting, single file, at a red light. The moment that the light turns green, the first car begins to accelerate, but you do not move. Each car must wait for the car in front of them to displace in order to proceed forward. It is the same for the system of masses.
If a force is imparted on the first mass, there will be a time delay before the effect of this force is felt by the tenth mass. We can think of the springs like spaces between cars, and the masses as the cars themselves. This analogy is far from perfect. For one thing, cars are more independent than this model would suggest. Car 1 is unaffected by all those behind it, whereas the motion of
mass 1 is greatly affected by the motion of those behind it.
