i want to know about earths gravity fieldthis question is related to geology
The speed of an object falling freely near Earth's surface is affected by the pull of gravity. It will fall at approximately 9.81 meters per second, per second. Of course, air resistance has an effect too. Because Earth is not a perfect sphere, but is instead, an oblate spheroid, the gravity field is not uniform. Factors affecting the gravity pull on an object on Earth include, altitude, latitude, topography and geology. The closer an object is to the Equator, by the equatorial bulge, means objects at the Equator are farther from the planet's center, than objects are at the poles, where the diameter is shorter. The pull of gravity is less at the equator, than at the poles. Weight is determined by the pull of gravity on a mass. Therefore, a person on a scale at the equator would weigh slightly less than at the poles.