the physics behind diving in the snow
Living in Rochester, I highly doubt anyone has been afforded the luxury of not having to drive in the snow, whether doing the driving yourself or just riding in the car with someone else. I've certainly had a few terrifying experiences in the snow, from not being able to see, to not being able to stop, to just outright totally losing control, but what factors play into this lovely experience known as winter driving that causes these wonderful situations? Well, to answer this question as well as I can, we first have to start with the basics of a car. Cars are able to move because an engine withing the car is powered by explosions of the gasoline within the engine, which generates a force which is then used to spin the wheels of the car. once the wheels are able to start spinning, a torque is created which is necessary to move the car. Friction must remain maintained between the tires and the road, however, for the duration of the drive in order to be able to move, similar to how there must be friction between your feet and the ground in order for you to walk forward. Now that this concept is out of the way, we can get into how snow effects these mechanics. The coefficient of friction between rubber and dry pavement is .67. This provides enough grip to move a car where it needs to go effectively. On wet pavement, however, the coefficient of friction decreases to .53, which is certainly enough to impact driving, especially at high speeds. But what about in snowy or icy conditions? Well, the coefficient of friction between rubber and ice is .15. this is less than a forth of the coefficient of friction between rubber and dry pavement, and less than a third of rubber on wet pavement, so, next time you're about to round that icy corner, just think about that. There are some things that can be done to increase friction when roads get icy or snowy, such as add weight, or even pus snow tires on your car. the increased weight will increase the downward normal force on the car, which will in turn increase friction, however, this added weight will also increase stopping distance, and on an already slippery road, that's probably not the best option. snow tires, however, are designed with a different rubber compound that remains more flexible in colder conditions, while a traditional summer or all season tire would stiffen and become less effective. They also provide a much deeper tread than an all season tire, and are designed with he intent of throwing snow out from underneath the tire, rather than just drive over it. with all of these factors in mind, it is easy to see why winter driving is always such a unique experience.