Gravitational fields Flashcards
What it a force field?
A region in which a body experiences a non-contact force. They arise from the interation of mass, of static charge, and between moving charges.
Define gravitational potential
The work done per unit mass required to
move a small test mass from infinity to that point.
Define gravitational field
A region surrounding a mass in which any other object with
mass will experience an attractive force.
What is an equipotential surface?
A surface of constant potential. No work is done by the field when an object moves along an equipotential.
What is the total energy of an orbiting satellite made up of?
Its kinetic and potential energy and is constant
Define escape velocity
the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.
What is a synchronous orbit?
An orbit in which the period of the orbit is equal to the rotational period of the object that it is orbiting.
What are satellites in low orbits used for?
Monitoring the weather, making scientific observations, military applications
What is a geostationary satellite?
A satellite that orbits above the equator with a 24 hour period, so it will always remain above the same position on the Earth.
What are geostationary satellites used for?
Sending TV and telephone signals, Navigation
Derive T^2 is proportional to r^3 (Kepler’s third law)
Use F=GMm/ R^2
And F=mw^2 or mv^2/R
