18.Gravitational Fields Flashcards
Escape Velocity
The minimum velocity required by an object to be able to
escape a gravitational field of a mass when projected vertically from its surface.
Field Lines
A line representing the path that a mass would take when placed
within the field.
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. They orbit approximately 36,000km above the surface of the Earth.
Gravitational Field Strength
The force per unit mass exerted on a small test mass placed within the field.
Gravitational Field
A region surrounding a mass in which any other object with
mass will experience an attractive force.
Gravitational Potential Energy
The component of an object’s energy due to its position in a gravitational field.
Gravitational Potential
The work done per unit mass required to move a small
test mass from infinity to that point.
Kepler’s First Law
All planets travel in elliptical orbits, centred around the sun.
Kepler’s Second Law
All planets sweep out the same area in a given period of
time.
Kepler’s Third Law
The square of a planet’s period is directly proportional to the
cube of its mean distance to the sun.
Newton’s Law of Gravitation
The force between two masses is proportional to
the product of the masses involved and inversely proportional to the square of the separation of the masses.
