Unit 18 - Gravitational Fields Flashcards
What is gravity?
= gravitational field
a universal attraction between any two masses
What is weight?
The force due to gravity, also known as gravitational force.
What is gravitational field strength?
Gravitational fields strength is the force per unit mass exerted by a gravitational field on an object
What is the perihelion?
The closest distance in orbit to the sun
What is the aphelion?
Furthest distance in orbit from the sun
What is the semi-minor axis?
From the centre and the narrowest part of the ellipse
What is the semi-major axis?
distance from the centre (halfway between the foci) and the widest part of the ellipse
What is the eccentricity of an ellipse?
how long and narrow it is
How is the eccentricity of an ellipse effected by how close the foci are?
The further the foci are from each other, the more eccentric it is
What is a satellite?
A body that circles around another body in space. Moons, comets, planets and stars are examples of natural satellites
What is the value of gravitational potential energy?
Defined as being zero at infinity and measured from there. (All values are negative)
What is gravitational potential?
The amount of energy required to move something per kg
What is Newton’s law of gravitation?
The gravitational force is directly proportional to the product of the masses and inversely proportional to the square of the distance
