- A physical body will remain at rest, or continue to move at a constant velocity, unless an external net force acts upon it.
- The net force on a body is equal to its mass multiplied by its acceleration.
- For every action there is an equal and opposite reaction.
How will this help me to drive in snow, you say? Very simple. These three laws (particularly the first one) form the basis for the cardinal rule of winter driving:
Any change in velocity must be done gradually.
- If you speed up, do it gradually.
- If you slow down, do it gradually.
- If you make a turn, do it gradually.
Driving in a straight line at constant speed means that you will continue going in a straight line at constant speed. You won't wind up in a ditch. That is for the idiots who think that the laws of physics are suspended for them because they happen to have 4-wheel drive.You are not safer because you're driving slowly. You're safer because you're driving in a straight line. In fact, driving slowly can pose just as much a hazard as the 4-wheel-drive idiots who don't know what they're doing. Driving slowly means (for instance) that you won't have enough momentum to make it up a hill - you'll start sliding backwards, and then you'll end up in a ditch.
2nd Corollary (for idiots - repeat 50 times, or however many times it takes to sink in):
Having 4-wheel drive does not make me invincible. The laws of physics still apply to me. I still have to make changes in velocity gradually. If not, I will wind up in a ditch, 4-wheel drive and all.