Frictional force direction

[JimmyRay]

lol... sorry for posting again but now I am confused about frictional force on my roller coaster....

When an object reaches the top of the loop of a roller coaster, what direction is it traveling in? Friction force will be opposite of that direction... At the exact top of the roller coaster, the surface is not curved correct? It's straight, and so will the object be travelling straight up (y direction) or straight horzinatal (x direction) ....

[cyby]

Your coaster is moving forward, tangent to the curve. In your case, either +x or -x, depending on how your coordinates are set up. There is no vertical component to your velocity on top, just horizontal ones....

[JimmyRay]

thats right, thank you :)