# Frictionless Bank

1. Sep 27, 2006

### Rawr

Which force is responsible for holding a car in a frictionless banked curve?

The answer is the horizontal component of the normal force. But could anyone explain why that is?

I thought it would be the horizontal component of the weight since normal force is vertical?

2. Sep 27, 2006

### Staff: Mentor

The weight acts vertically--it has no horizontal component. The normal force is perpendicular to the road surface; since the road is banked (at an angle) that normal force is not vertical.

3. Sep 28, 2006

### civil_dude

This is a rotational velocity problem. There are two kinda 'normal' forces here. The real vertical normal force to resist gravity, and the horizontal force in the 'normal' directionto accelerate the object along a curve.

Last edited: Sep 28, 2006
4. Sep 28, 2006

### Staff: Mentor

This is a problem involving circular motion and thus centripetal acceleration. There is only one normal force, which is perpendicular to the road surface. That normal force has vertical and horizontal components.