🧵 Untitled Thread
Anonymous at Wed, 24 Jul 2024 19:17:50 UTC No. 16295072
What creates the force that causes cars to turn when their front wheels turn?
Is it because most steering systems rotate the wheels off center which causes the friction force created by the rotated wheels to be offset from it's center of mass, thus making it rotate??? Imagine a tricyle with the axis used to steer perfectly perpendicular to the ground can it steer or will steering merely slow it down (given that the steering axis of this vehicle cannot bend)?
Anonymous at Wed, 24 Jul 2024 19:25:52 UTC No. 16295080
Imagine friction as a vector and it will become clear.
Anonymous at Wed, 24 Jul 2024 19:26:55 UTC No. 16295085
>>16295072
Friction.
In particular, much more lateral friction than there is longitudinal friction in the form of rolling resistance. Thus the effective force is pretty much sideways, as the lateral component dominates.
Anonymous at Wed, 24 Jul 2024 19:50:14 UTC No. 16295120
>>16295085
why is the force of friction lateral
Anonymous at Wed, 24 Jul 2024 19:56:40 UTC No. 16295129
>>16295120
because the wheels were rotated
Anonymous at Wed, 24 Jul 2024 19:56:47 UTC No. 16295130
>>16295120
Because the wheels are turned so the vector is angled to the side and not directly with the momentum
Anonymous at Wed, 24 Jul 2024 19:58:57 UTC No. 16295133
Imagine the wheels as pushing outwards from their center, both equal and opposite, due to friction.
When you rotate a wheel, it pushes out in the direction of motion as well as slightly orthogonal to the direction of motion, which pushes the car in the way the wheel is facing. The other wheel pushing into and against the turn, which gives you radius rather than a straight shot
Anonymous at Wed, 24 Jul 2024 20:00:11 UTC No. 16295135
this queston was stillborn
Anonymous at Wed, 24 Jul 2024 20:09:58 UTC No. 16295155
>>16295133
yeah but where does this orthogonal force come from
Anonymous at Wed, 24 Jul 2024 20:17:00 UTC No. 16295171
>>16295155
Take a wheel, and roll it forwards.
Take the same wheel, and try to push it perpendicularly (without tipping it).
Friction.
Anonymous at Wed, 24 Jul 2024 20:31:42 UTC No. 16295199
>>16295171
nah I put a wheel on a hill diagonally and get confused about why it rolls diagonally.
>obviously Because there's less friction in that direction for the wheel
How do you get from newtons laws to the fact that in this case the wheel takes the path of least resistance?
Anonymous at Wed, 24 Jul 2024 20:38:27 UTC No. 16295211
>>16295199
>nah I put a wheel on a hill diagonally and get confused about why it rolls diagonally.
The friction of rolling is much less than the friction of sliding. It rolls one way, and to go the other it slides into friction.
Friction pushes out from the wheel, not along its path, ideally.
Anonymous at Wed, 24 Jul 2024 20:53:18 UTC No. 16295238
>>16295211
But why does it decide to roll?
Anonymous at Wed, 24 Jul 2024 20:54:11 UTC No. 16295239
>>16295238
Because rolling is cheap, and rolling in the way it's facing is cheapest. So if you set it diagonally, it will roll diagonally.
Anonymous at Wed, 24 Jul 2024 20:56:36 UTC No. 16295244
>>16295238
ah wait because of the normal force of the surface ....
Anonymous at Wed, 24 Jul 2024 21:19:36 UTC No. 16295270
>>16295239
yeah but how do i get that result using force vectors
Anonymous at Wed, 24 Jul 2024 21:31:11 UTC No. 16295281
>>16295270
friction only acts in the direction opposite motion.
When you're moving forward at an angle to the front wheels, the wheel rolls and is pushed by momentum, but friction pushes back.
You're left only with rolling.
Anonymous at Thu, 25 Jul 2024 00:42:04 UTC No. 16295437
wtf is this? actual science being discussed?
well i'll be
Anonymous at Thu, 25 Jul 2024 20:57:06 UTC No. 16296480
>>16295072
While free wheeling, the wheels are free to roll with the road surface longitudinally, producing little longitudinal force. With a slight steering angle however, it will create a slight lateral motion to the outside, which with friction will create force towards the inside. It also produce some longitudinal force which is not shown on the graph.
For bike/car with negative camber, leaning the wheel towards the turning center also effectively turning the rolling surface to a cone, which will also roll towards the center.
You can read more on the-contact-patch.com/book/road/c17