gravational fields Flashcards
Definition of a Gravitational Field
A region of space where an object with mass experiences a force.
Objects with mass create gravitational fields around them.
what is Gravitational Force
Always attractive.
Acts between any two objects with mass.
what is Gravitational Field Strength
Measured in N/kg (same as m/s²).
Represents the force per unit mass in a gravitational field.
what are the two types of Gravitational Field Lines
Radial field: Field lines spread out from a point mass.
Uniform field: Parallel and equidistant field lines, such as near Earth’s surface.
Newton’s Law of Gravitation
The force between two masses depends on their size and the distance between them.
The further apart the objects, the weaker the force.
Kepler’s First Law
Planets move in elliptical orbits around the Sun, with the Sun at one focus.
Kepler’s Second Law
A line from the planet to the Sun sweeps out equal areas in equal time.
Planets move faster when closer to the Sun.
Kepler’s Third Law
The time a planet takes to orbit the Sun is related to its average distance from the Sun.
Definition of a Satellite
A body that orbits a planet or star due to gravitational attraction.
Forces Acting on a Satellite
Only force acting is gravitational attraction from the Earth.
No air resistance if above the atmosphere.
what is Polar Orbit
Passes over the poles.
Provides a full view of Earth over time.
Used for mapping and surveillance.
what Geostationary Orbit
Remains above the same point on Earth.
Must orbit the equator and match Earth’s rotation.
Used for communication and weather satellites.
Uses of Satellites
Communication
Used for TV, radio, and internet.
Military
Scientific Research
Weather Monitoring
Used for tracking storms and climate patterns.
what is Gravitational Potential
The work done per unit mass to move an object from infinity to a point in a gravitational field.
Zero at infinity and always negative elsewhere.
Why Gravitational Potential is Negative
Energy is required to separate masses since all masses attract each other.
what is gravitational potential energy
The energy stored in an object due to its position in a gravitational field.
Increases as you move an object further away from a planet.
