Before that let understand meaning of Gravity
Gravity is a force that for us is always directed downwards. But to say that gravity acts downwards is not correct. Gravity acts down, no matter where you stand on the Earth. It is better to say that on Earth
Gravity is a force that attracts objects together. On earth this force attracts everything to Earth.
We can represent the force of gravitational attraction as a field. A field is a graphical representation of the strength of a force and the direction in which the force is felt.
The space around a body within which its gravitational force of attraction is experienced, is called its gravitatio
nal field.
In a local region on the surface of the Earth the gravitational field is essentially uniform. We can see this because the number of field lines per unit are does not change. If the force was stronger in a particular region, the number of field lines in that region would increase. The lines of force act downwards toward the centre of the Earth but on this scale the gravitational field is uniform
On a larger scale, the gravitational field varies in direction and magnitude. The direction of the field li
nes is perpendicular to the surface of the Earth. As the height above the surface of the Earth increases the magnitude of the force decreases as is shown by the increasing separation of the field lines.
Considering the Earth as whole, the gravitational field is directed toward the centre of the Earth. On opposite sides of the Earth the gravitational field has an opposite magnitude.
No comments:
Post a Comment