Why does the rotation of a wheel on a car force the car to move? I was told it was due to the wheel ‘pushing the ground and propelling the car,’ but this seems a little basic.

Question

I know it seems stupid but I can’t grasp the Physics behind it.

Thanks.

In: Physics

Answer 1

ELI5: when you put heavy things on a tire (like a car) it squishes it a little bit. So it is not a perfect circle anymore. For the sake of visualization imagine that it is REALLY squished and looks more like tracks on a tank. As the tire/track spins the flatter part that is touching the ground is really only moving backwards for that short time. There are 3 things that could happen in this scenario. The ground could move, the car could move, or the tire could just spin without either of them moving.
Other than in sand or other loose soil the ground won’t normally move much, and other than times with slippery things like ice or snow normally the tire won’t just spin so that leaves the last option. Normally it makes the car move.