The g-force or gravitational force equivalent is mass-specific force, expressed in units of standard gravity.
It is used for sustained accelerations, that cause a perception of weight. For example, an object at rest on Earth's surface is subject to 1 g, equaling the conventional value of gravitational acceleration on Earth, about 9.8 m/s2.
More transient acceleration, accompanied with significant jerk, is called shock.
This top-fuel dragster can accelerate from zero to 160 kilometres per hour (99 mph) in 0.86 seconds. This is a horizontal acceleration of 5.3 g. Combining this with the vertical g-force in the stationary case using the Pythagorean theorem yields a g-force of 5.4 g.
This acrobatic airplane is pulling up in a +g maneuver; the pilot is experiencing several g's of inertial acceleration in addition to the force of gravity. The cumulative vertical axis forces acting upon his body make him momentarily 'weigh' many times more than normal.
The Superman: Escape from Krypton roller coaster at Six Flags Magic Mountain provides 6.5 seconds of ballistic weightlessness.
In science and engineering, the weight of an object, is the force acting on the object due to acceleration of gravity.
A weighbridge, used for weighing trucks
Image: Weegschaal 1
Image: Bascula 9
