* How Stuff Works - An Introductory

[LateNightCable]

Originally Posted by GIR x = 10000 y(10000) = 10000/(1+10000) = 10000/10001 = 0.99999999999999999

I think you missed a 9. Okay okay, this is a serious thread for educational purposes, peace out.

[reggid]

Originally Posted by GIR Your car wants to move forward so it excerts a force onto the road. But the road doesn't like this so it tries to hold the car in place as much as possible. The faster you go the smaller this drag becomes. Well the amount of force excerted onto the road is infinite times bigger then the drag cause by the road so we can say that it's actually not there.

When the car exerts a force on the road doesn't the road apply an equal but opposite force to the car?
The only thing that can stop it moving is some force in the opposite direction (to the force the road exerts on the car).
I don't see by what mechanism/law of physics this force you call drag arises from?
I'm not trying to be a pain, but maybe i already know what your talking about, and its simply just that your using a different word/explanation to describe it!!!

[GIR]

Drag is caused by the moving of friction areas. Like you said turning parts of the car cause drag aswell, but that's not nearly as much as the drag caused by the road on the tires.

No that's only when the car is standing still. When the car is standing still all forces are equal and opposite to eachother. That's what's keeping the car in place. When you start moving the force that was keeping the car in place is still there but at some point it becomes so small (infinitly small) that we say it's not there anymore.

Like in the math example when x = 10000. In that situation the answer should be 0.999999999 etc. For convinience we say that it's not 0.99999999 but 1. It doesn't make much of difference for the final answer.

Same goes for the drag. At some point it's so small in the view of the energy output of the car that it doesn't matter much anymore wether we do or don't take it along in our equations so we say that it's not there anymore.

[thepolarfoxqx]

simpy put, when a car travel through any given space, it has to move the air in it out of its way, so the force of the car pushing the air out of the way has an opposite but equal, the air pushing back on the car.

most of the rolling resistance is just friction, molecules in the tire rubbing up against each other, turning energy created by the car into heat instead of forward momentum.