Website Address: https://library.curriki.org/oer/Centripetal-Force
This image shows the inertial force of the coaster car (the yellow arrows) and the centripetal force of the track (the orange arrows) that result in the coaster car moving in a loop (centripetal motion) along the roller coaster.
Original Image (w/o arrows) by J.delanoy. License: CC-BY-SA. Source: http://commons.wikimedia.org/wiki/File:Roller_coaster_vertical_loop.ogg Modified image (w/arrows) by Meredith Beaton. License: CC-BY-SA