tyngdeaccelerationsvärden

Tyngdeacceleration, commonly referred to as gravitational acceleration and denoted g, is the acceleration that a body experiences toward the center of a massive body, such as the Earth, due to gravity. On Earth, g describes how quickly an object speeds up when dropped, if air resistance is neglected.

The value of g is not exactly constant; it varies with location because of changes in Earth’s shape, rotation, and density. In Newtonian form, g = GM/r^2, where G is the gravitational constant, M is the mass of the attracting body, and r is the distance from its center. Near Earth's surface, g is about 9.8 m/s^2, but ranges from roughly 9.78 to 9.83 m/s^2 depending on latitude and altitude. The equator is weaker due to the centrifugal effect of Earth's rotation.

The standard or nominal gravity, denoted g0, is defined as 9.80665 m/s^2 for calibration and engineering purposes. This value is referred to as international standard gravity and is used in the definition of many physical constants and in engineering calculations.

In everyday terms, weight W is the product of mass m and gravitational acceleration: W = mg. Gravitational acceleration is an acceleration quantity, while weight is a force. In rotating frames or at different planetary bodies, the effective gravity can differ from g due to centrifugal effects or variations in radius and mass.

Beyond Earth, g decreases with distance from a planet’s center and increases with a more massive body. Values are known for other planets and moons and are crucial for mission planning and vehicle design.