# Direction of the gravtional force on the earth

1. Mar 8, 2009

### tnutty

At the moment of the earth and sun, what is the direction of the gravitational force acting on the earth?

this is practice. So the direction could be either,

y+, y-, x+, x- on a coordinate system as you can imagine.

I am thinking its y+
meaning that its force is pulling?

2. Mar 8, 2009

### Nabeshin

Gravity always acts on the line joining the two bodies, pointing towards the other body. (So the force of gravity on the Earth points towards the sun and that on the sun towards the Earth).

So at any point during the orbit the direction of the force could be any combination of y and x components, provided it is pointing directly towards the sun.

3. Mar 8, 2009

### tnutty

Hey, thanks, now i understand better.

So i am assuming that the earth rotates in an oval shape because of the different gravitational force in space.

4. Mar 8, 2009

### Nabeshin

Right, the shape of the Earth's orbit is an ellipse which is a consequence of the fact that gravity scales with the inverse square of the distance.