"What is the force that puts the thrill in thrill rides? Gravity, of course! One of the biggest challenges for Imagineers in designing theme park attractions, like Disney's Rockin' Roller Coaster and The Twilight Zone Tower of Terror, is figuring out the best way to work with-and sometimes against-gravity's constant 1G force. Learn to define gravity and explain the relationship between gravity, mass, and distance. Apply an understanding of forces to explain the feeling of weightlessness on a rollercoaster ride"--Container.