What’s Up with G-forces?

Fighter pilots and racecar drivers deal with serious g-loads every day. But what exactly are they?

by Mika Grondahl
Mika Grondahl

G-FORCE--WHAT IS IT?
You've seen us mention g-forces in articles about new jet aircraft and cars?many times with reference to their being a very serious obstacle to overcome when developing ever faster technology. But what are they? Gravitational force is the force of gravity pulling you toward the Earth. When you undergo a change in speed and direction, that force increases in proportion to the rate of change. To calculate the magnitude of the force you feel as g's increase, multiply your weight by the number of g's.

WHEN DO YOU FEEL IT?
Most of us encounter g-force during a hard turn in a car or while hurtling along in a roller coaster (in other words, not too often). Fighter pilots, however, experience g-force "with every maneuver you make," says U.S. Air Force First Lt. James Morgan. "If we are in a dogfight, we're never going to go straight?we're going to be constantly turning."

HOW MUCH WHEN ...