Physics

Phy

Define Gravitational Potential,V  is

Work done in bringing/moving unit mass

from infinity to the point

V=-GM/r

(note:since it only a unit mass so its only have one M)

whereas 

Define Gravitational Potential Energy,U is

Work done in bringing/moving the mass

from infinity to the point P

U=-GMm/r

see the differences??

so let me explain 

basically both may look the same but it's not

the formula for both also difference..

The key point here is that 

Gravitational Potential apply for a unit mass
+ no specifics point state.. for infinity to what point??

while 

Gravitational Potential Energy for the mass and specifically state point P

:)

Q:Why is the latent heat of vaporization is greater than the latent heat of fusion? A:The energy required to completely separate the molecules, moving from liquid to gas, is much greater that if you were just to reduce their separation, solid to liquid.
In addition, based from what my teacher said was that to change state of the molecules from liquid to gas, the molecules need to overcome the atmospheric pressure on the molecules to completely become gas. So more energy is needed to overcome the atmospheric pressure.

Hence the reason why the latent heat of vaporization is greater that the latent heat of fusion.

http://www.scribd.com/doc/33017680/Why-is-the-latent-heat-of-vaporization-of-water-greater-than-the-latent-heat-of-fusion-of-water