Gravitational Fields Flashcards
What is Gravity?
Gravity is an attractive force between all particles with mass
What is G?
The gravitational constant (6.67E-11)
What can field lines tell you about a gravitational field?
The direction of the field and the strength of the field depending on their density
What is g?
Gravitational field strength - the force per unit mass in a gravitational field
What is gravitational potential?
The potential energy per kg. It is negative, but 0 at infinity.
What is the work done by moving a mass in a gravitational field?
Mass x Change in Potential
What is the Gravitational Potential Difference?
The difference between the gravitational potential at 2 points in a field
What is an equipotential surface?
A surface in which every point on it has the same potential
How much work is done when you move 1km in any direction on an equipotential?
No work is done when moving across equipotentials as the potential at each point is the same
Why is gravitational potential a negative value?
Work needs to be done to move an object from that point to infinity, and infinity is 0
How is the orbital period related to the radius of a circular orbit?
T² is directly proportional to R³
Compare the PE and KE of a lower orbit to a higher one
A lower orbit has less PE and more KE than a higher orbit
What is the period of a geosynchronous orbit?
1 day
What is the formula for gravitational field strength?
g = F/m
What equation do you use to calculate escape velocity?
½mv² = (GMm)/r Where v = escape velocity
