Newtonian world and astrophysics: Gravitational fields Flashcards
what is gravity
the univeral attractive force between all matter
what do gravitational field lines communicate
thee direction of the field and strength of the field
what i g
g is the force per unit mass
What is newtons law of gravitation
any two point masses attract each other with a force proportional to the product of their masses and inversely proportional to the square of differences between them
what is Keplers first law
the orbit of a planet is elliptical with the sun at one of the foci
what is keplers second law
during equal areas of time, the area swept out between the sun and the planet is equal
what is keplers third law
the square of the orbital period is proportional to the cube of the average distance form the sun
what are satellites
a satellite is an object that orbits a larger planet
what is special about a geostationary atelite
their orbital period is exactly one day
what is gravitational potential
the potential energy per unit mass at a point in the field where at infinite distance, potential =0
what is GPE at a point in the field
the work done per unit mass in moving an object from inifity to that point in the field
what is escape velocity
the minimum velocity an object requires in order to escape the gravitational fiel of an object
