Question

Gravity anything with mass as gravity we know the earth has gravity because you and I are standing on earth and not floating off into space when we jump we come right back to earth which model best represents the force of gravity pulling us all down to earth?

Answer 1

`F=mg`

Step-by-step explanation:

Close to Earth's surface, the force of gravity that pulls an object towards the ground is

`F=mg` (2)

where

m is the mass of the object

g is the acceleration due to gravity, which is
`9.81 m/s^2` close to Earth's surface

This is an approximation of the general formula of gravity valid only close to Earth's surface. The more general formula is

`F=G(Mm)/(r^2)` (1)

where

G is the gravitational constant

M is the Earth's mass

m is the object's mass

r is the distance of the object from Earth's center

At the Earth's surface,

r = R (Earth's radius), and by calling the following factor

`g=(GM)/(R^2)`

we see that eq.(1) becomes eq.(2).