# Gravitational Potential

1. Jun 23, 2013

### Knightycloud

Gravitational potential is always a negative value according to the theory.
As per to the equation V = - $\frac{GM}{r}$; when the r (distance) increases the potential decreases. But considering the potential at infinity as zero and since this a negative value, on what basis do we consider the potential is decreasing, not increasing (When the distance is increasing)?

2. Jun 23, 2013

### Staff: Mentor

No. As r increases, 1/r decreases, but -1/r increases.

3. Jun 24, 2013

### sophiecentaur

i.e. it's less negative.

4. Jun 24, 2013

### Staff: Mentor

...or slopes upward (has a positive slope) on a graph of V versus r.

5. Jun 24, 2013

### sophiecentaur

'Everywhere' is the equivalent of 'underground', effectively and up is up, however deep or high you are.

6. Jun 25, 2013

### Knightycloud

So as the negative value decreases, potential is increasing accordingly?

Let's say that the potential on earth surface is Va = -$\frac{GM}{R}$ and if we move to a higher place where the distance is twice, the potential is Vb = -$\frac{GM}{2R}$. But at Vb, the negative value is smaller than Va, Vb has a higher potential. Right?

7. Jun 25, 2013

### sophiecentaur

It's exactly the same as when you deal with xy co ordinates. Moving tp the right is increasing the x co ordinate, whether you start on the right or to the left of the origin. Just let the Maths work for you.
And you really mean 'magnitude'.

8. Jun 30, 2013

### Knightycloud

Yep. I got answers. Thank you all!!! :D