'banked curves' physics works in terms of circular motion

[run-bandit]

I don't understand how 'banked curves' physics works in terms of circular motion. Since friction apposes motion, and at any moment your velocity (motion) is tangental to your circular path, then that should mean your friction force DOES NOT contribute to the centripetal force but rather to a slightly askew backwards thing at the next moment (assuming a slight time delay for the application of forces)How can this thing work? hurr durr why does increasing friction magically make centripetal force more and easier to go around in a circle?

[Akirus]

In certain locomotion such as walking, wheels, etc, the frictional force is what pushes you forward. Too tired to explain though, someone else will do it.

[kamil9876]

Have you looked at the basic case of box/particle sliding down a ramp with friction?

[stonecold]

lol at thread title.  this is exactly what i was feeling a week ago haha.

[QuantumJG]

I don't understand how 'banked curves' physics works in terms of circular motion. Since friction apposes motion, and at any moment your velocity (motion) is tangental to your circular path, then that should mean your friction force DOES NOT contribute to the centripetal force but rather to a slightly askew backwards thing at the next moment (assuming a slight time delay for the application of forces)How can this thing work? hurr durr why does increasing friction magically make centripetal force more and easier to go around in a circle?

I remember being confused with this and it's much simpler than you think.
 
At car races you will see the curves are banked, but why?

First let's take a piece of the ramp with say a box on it, you will notice that the normal force points out and makes a 90^o with the ramp. So you get a component of the normal force pointing into the centre. If the net force equals the centripetal force this means:

F_cent = n + F_traction

So the track being banked allows part of the normal force to contribute to the centripetal force, which is a great advantage for racing since if the track is banked, the car can go around at a faster speed that may make the car fly off if it were on a flat track.

I hope this helps.

[Akirus]

I don't understand how 'banked curves' physics works in terms of circular motion. Since friction apposes motion, and at any moment your velocity (motion) is tangental to your circular path, then that should mean your friction force DOES NOT contribute to the centripetal force but rather to a slightly askew backwards thing at the next moment (assuming a slight time delay for the application of forces)How can this thing work? hurr durr why does increasing friction magically make centripetal force more and easier to go around in a circle?

I remember being confused with this and it's much simpler than you think.
 
At car races you will see the curves are banked, but why?

First let's take a piece of the ramp with say a box on it, you will notice that the normal force points out and makes a 90^o with the ramp. So you get a component of the normal force pointing into the centre. If the net force equals the centripetal force this means:

F_cent = n + F_traction

So the track being banked allows part of the normal force to contribute to the centripetal force, which is a great advantage for racing since if the track is banked, the car can go around at a faster speed that may make the car fly off if it were on a flat track.

I hope this helps.

That's not what he's asking. He's confused as to why the frictional force does not hinder the motion of the vehicle.

[/0]

If you vectorially add the 'backwards' and 'sideways' friction forces you will get a 'slightly skewed' resultant force. However, you can simply take the centripetal component of that force (the component which is directed towards the centre).

[QuantumJG]

In terms of uniform circular motion, the friction component that we are interested in is just the centripetal component that is stoping the car from going off on a tangent, this is analogous to standing on a wet floor and slipping from providing a stronger force with your foot than what the friction can stop.

If you were to talk about non-uniform acceleration (Not covered in VCE), then you would get some retardation force trying to oppose the tangential acceleration that is accelerating your car about the track.