The weather is blessedly humidity-free, the lines are surprisingly short and you're ready for a day full of barrel rolls, dog legs and headchoppers. Before you board that imposing and intriguing coaster, make sure you know what these and other terms mean.

First, ask yourself these questions:

1) You just rode a launch coaster that made you experience negative Gs as you went over a camelback. What happened to you?

A. You experienced weightlessness as a result of being flung at 80 mph over a series of small hills.
B. You experienced motion sickness.
C. You experienced being completely disoriented in less than two seconds.
D. All of the above.

2) During a night ride on a stand-up hypercoaster you go through a series of inversions and under a headchopper. What just happened?

A. You rode a 200-foot-high stand-up roller coaster at night.
B. You were turned upside down several times.
C. You went under a bridge and had the sensation that you might be decapitated.
D. All of the above.

If you didn't answer D to both of the above questions, use this list of 20 words and phrases to help understand what may happen to you on your favorite ride.

Airtime: The sensation of weightlessness while riding a coaster. This usually happens when going over a hill or during a drop, and is also known as negative G forces, or coming out of your seat. Apollo's Chariot in Busch Gardens Williamsburg is one of only five coasters in the park, but its 73-mph speed and multiple opportunities for airtime make up for it.

Barrel roll: A complete sideways twist that sends a train into a 360-degree roll, taken from a jet-fighter maneuver. Six Flags America's newest coaster, Storm Runner, features a barrel roll.

Camelback: A series of two or more hills, each one smaller than the last. Paramount's Kings Dominion's Hurler thrills with two camelbacks.

Dark ride: A roller coaster that is completely enclosed, enhancing the sensation of the ride since you can't anticipate its dips and turns. Kings Dominion features the Flight of Fear, an alien-themed dark ride that is sure to scare you out of your skin.

Dead spot: Part of a coaster ride where the train loses all momentum and intensity and just rambles along. Too much of this can ruin a coaster. Often, it exists as a long, straight and flat piece of track. Although the Rebel Yell at Kings Dominion has a few dead spots, these do not ruin the ride -- you need them to catch your breath.

Dog leg: A sharp bend in an otherwise straight track. The Wild One at Six Flags has a number of these turns.