Gravitational Fields Flashcards
What is gravity (simple)
A weak force that occurs between any objects with mass
In what direction are gravitational fields always directed
The object of mass producing the field
How do we treat gravitational fields of spherical bodies
As though the whole mass of the object is concentrated at the center of the body
Gravitational field strength
The force experienced per unit mass by a mass placed in the field
What are the units for gravitational field strength
Newtons per Kilogram, NKg^-1
What type of quantity is gravitational field strength
It is a vector, as such it has direction, which is the direction in which a mass moves when within the field
What is the gravitational field strength at any point in a gravitational field equal to
The acceleration due to gravity
Newton’s law of gravitation
The gravitational force between two particles is proportional to the product of their masses and inversely proportional to their separation squared
What are the units of Newton’s law of gravitation
N
Gravitational Potential
The work done per unit mass in bringing a mass from infinity to that point
What are the units of gravitational potential
Joules per Kilogram, JKg^-1
What kind of quantity is gravitational potential
Scalar
Explain why gravitational potential is always negative
Since potential at infinity is zero, when an object moves towards infinity it has to do work due to the direction of the field lines. This means that the potential increases as we move towards infinity, so it has to be negative
Potential Energy
If a mass is placed in a gravitational field then it will have potential energy
What is the area under a F-r graph equal to
Work Done
