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