# Question #48cbd

Aug 17, 2015

gravity due to force of attraction of earth

#### Explanation:

gravity is the force of attraction that applied by earth on the objects.Due to gravity,every objects attracted towards the center of earth.

Aug 18, 2015

All objects in the universe exert a gravitational force on each other. This force is proportional to the product of their masses and inversely proportional to the square of the distance between them.

#### Explanation:

The magnitude of the force between two objects can be calculated as follows:

$F = G \frac{M m}{R} ^ 2$

Where $G$ is the universal gravitational constant, $M$ and $m$ are the masses of the two objects, and $R$ is the distance between them.

Near the earth's surface (which is where you live) we can simplify and just calculate the force of gravity from the earth as:
$F = m g$
That small letter $g$ is really:
$g = G \frac{M}{R} ^ 2$
Where $M$ is the mass of the earth and $R$ is the radius of the earth. Going up a few kilometers or down a few kilometers doesn't change your distance from the earth's center by a large fraction. For most purposes, $g$ can be considered to be constant.