As of April, 2004, the biggest roller coaster in the world was the Millennium Force at Cedar Point Park in Ohio. The first drop falls 305 feet at an 80-degree angle:
Image copyright Joe Schwartz and courtesy of www.rcdb.com
At the bottom of the drop, the track rises into a second hill of height 180 feet, which includes a 180-degree turn. The turn is very roughly half of a circle with a radius of about 150 feet.
Image copyright Mark Rehak and courtesy of www.rcdb.com
If we ignore friction and air resistance,
Copyright © Michael Richmond. This work is licensed under a Creative Commons License.