# Normal force direction

1. Dec 14, 2004

### JimmyRay

Hi I have to draw a freebody diagram for FN (normal force) of an object at different locations on my rollercoaster.

Where would FN be located when the object is upside down (going through a loop) .... would it just be straight down? (like gravity) ? Because FN is always perpendicular to the surface, so when the object is at the top of a loop on my roller coaster, FN would be straight down wouldn't it? And Ff would be straight up? And gravity is always down...........

2. Dec 14, 2004

### cyby

The force of friction is against the direction of the roller coaster's motion.

Gravity is always down, and the normal force at the top of the loop, would indeed be straight down.

Check this out...

http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/circmot/rcd.html [Broken]

Last edited by a moderator: May 1, 2017
3. Dec 14, 2004

### JimmyRay

Oh my god.... thank you soooooooooo much

4. Dec 14, 2004

### cyby

You are welcome :-D Sometimes google gives pretty good answers too, but it helps to know what to look for.