5.4 - Gravitational Fields Flashcards
What is a Gravitational Field?
The region around a body in which other bodies will feel a force due to the mass of the body
What are Gravitational Field Lines?
They show the shape of the field and the direction of the field at a point is the direction in which a small mass would move when placed at that point
What is the Gravitational Field Strength?
The force acting per unit mass, g=F/M
What is Newton’s Law of Gravitation?
It states that the gravitational force of attraction between two point masses is directly proportional to the product of their masses and inversely proportional to the square of their separation
What is Kepler’s Third Law?
It states the square or the period of a planet orbiting the Sun is proportional to the mean radius of its orbit cubed
What is a Geostationary Orbit?
An orbit of the Earth by a satellite that has the same time period and orbital direction as the rotation of the earth, and is in the equatorial plane
What is Gravitational Potential?
The work done in moving a unit mass from infinity to that point. Measured in Joules per Kilogram
What is Gravitational Potential Energy?
For a radial field around a point or spherical mass M, the gravitational potential energy at a distance r from M is defined at -(GMm)/r. Measured in Joules
What is Escape Velocity?
The minimum velocity required to move an object from that point to infinity
What is Kepler’s First Law?
Planets travel around the sun in elliptical orbits
What is Kepler’s Second Law?
A line joining the sun to a planet will sweep out equal areas in equal times
What is an empirical law?
A law based on available data without being based on any scientific theory or hypothesis
