10. Fields (AHL) Flashcards
Gravitational field
a region of space where a massive object experiences a force.
Electrostatic field
a region of space where a charged object experiences a force.
Electric potential
the work done per unit charge in moving a small unit positive test charge from infinity to that point.
Gravitational potential
the work done per unit mass in moving a small test mass from infinity to that point.
Newton’s law of graviation
the force of attraction between two massive objects is proportional to the product of the masses and inversely proportional to the square of their separation.
Coulomb’s law
the force between two charged objects is proportional to the product of the charges and inversely proportional to the square of their separation. A negative force is attractive, positive is repulsive.
Field line
A line used to show the direction of a field. (for electric field it shows the direction a positive charge would move)
Equipotential surface
A surface of constant potential. The work done to move a charge from any point on the equipotential surface to any other point on the equipotential surface is zero since they are at the same potential.
Electric potential energy
Energy a charged object possesses because of its position in an electric field
Gravitational potential energy
Energy a massive object possesses because of its position in a gravitational field
Potential gradient
The change in potential divided by the distance over which the change happens.
Potential difference
the difference of electrical potential between two points.
Escape velocity
the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.
Geosynchronous orbit
an orbit with a time period of 24 hours so the satellite appears to stay in the same region of the sky
Polar orbit
an orbit close to the Earth’s surface that often goes over the poles
Geostationary orbit
a special case of the geosynchronous orbit where the satellite orbits around the equator so will be stationary relative to the Earth.
Orbital energy
The sum of the potential and kinetic energies of an object in orbit
Uniform field
A field where the electric field strength is constant throughout the field.
Radial field
A field that is drawn from a central point and becomes weaker as the distance from the point increases.
