Design Speed

[sin0001]

At the design speed, there's no frictional force, but why is there still a net force directed towards the center of the circle, I thought by saying 'there's no frictional force at design speed' it is meant that there is no sideways force acting upon the object? Isn't frictional force the same as a sideways net force, I'm confused :S
Please Help!

[Aurelian]

At the design speed, there's no frictional force, but why is there still a net force directed towards the center of the circle, I thought by saying 'there's no frictional force at design speed' it is meant that there is no sideways force acting upon the object? Isn't frictional force the same as a sideways net force, I'm confused :S
Please Help!

Any lateral frictional force will act tangentially to the banked curve, not towards the centre of the circle in which the object is travelling. Does that help at all?

[paulsterio]

Are you talking about a banked curve or an unbanked curve?

For an unbanked curve, if there is no friction, you simply will not be able to turn. Think about driving on ice. If you attempt to turn a corner, you will just skid away.

If you're talking about a banked curve, then if there was no SIDEWAYS friction (important, because if no friction at all, you won't be moving ) the force towards the centre of the circle is due to the horizontal component of the normal reaction force.

Though do elaborate your question, because I'm not sure what you're trying to describe.

[sin0001]

This situation involves a banked curve, apologies for being vague!

[paulsterio]

In that case the force towards the centre of the circle is the horizontal component of the normal reaction force. Obviously the vertical component is "cancelled out" with the weight force.