Gravitation: Potential
Terms
Terms
Gravitational potential energy
-
Is defined by the integral:
Where
is the force due to gravity and we define
U(∞) = 0
. Doing the integral gives:
which reduces to U = mgh near the earth.
U(r) = - 
|
Where
is the force due to gravity and we define
U(∞) = 0
. Doing the integral gives:
U(r) = - 
|
which reduces to U = mgh near the earth.
Gravitational potential
-
Is defined as the gravitational potential energy that a 1 kilogram mass would have at some point in space. It is given by:
which reduces to Φ g = gh near the earth.
Φ
g = - 
|
which reduces to Φ g = gh near the earth.
Principle of Equivalence
-
Asserts that all types of matter fall at the same rate. That is,
g
for a brick is the same as
g
for water. This means that the inertial mass appearing in Newton's Second Law is equivalent to the gravitational mass appearing in the Universal Law of
Gravitation.
Gravitational mass
-
The mass that appears in the Universal Law of Gravitation.
Shell Theorem
-
States that any spherical mass can be treated as though all its mass were concentrated at its center for the purposes of calculating gravitational force. Also, that a spherical shell of matter exerts no gravitational force on a mass inside it.
Formulae
| Energy for a circular orbit around the sun |
|
