# Shared Flashcard Set

## Details

Gravitational Fields
A level gravitation
12
Physics
12/18/2012

Term
 What is Newton's Law of Universal Gravitation?
Definition
 Newton's Law of Universal Gravitation describes how ALL objects attract each other's mass with a force of gravitational attraction. The force of gravitational attraction is directly proportional to the masses of each of the objects and inversely proportional to the square of the distance that separates their centers.
Term
 What is the equation for gravitational force of attraction?
Definition
 [image]
Term
 What is G?
Definition
 The gravitational constant G = 6.673 x 10-11 N m2 kg-2
Term
 What is 'r'?
Definition
 distance between the centres of the masses is denoted by 'r'
Term
 What is 'g'?
Definition
 g is the gravitational field strength or the acceleration due to gravity - depends on the situation!
Term
 What are the units of 'g'
Definition
 When gfs the unit is N kg-1 but when acceleration due to gravity the unit is that of acceleration m s-2
Term
 What is the gravitational field strength at a point?
Definition
 The gravitational force per unit mass at that point.
Term
 Show that g = GM/r2
Definition
 g = F/m but F = GmM/r2 so, g = GM/r2
Term
 Is Gravitational Field strength a scalar or vector quantity?
Definition
 Gravitational Field strength is a vector because it has a direction - is a force per unit mass (and force is a vector!).
Term
 Is gravitational potential a scalar or a vector?
Definition
 It is a scalar quantity - 'energy required' and energy is scalar!
Term
 What is meant by the gravitational potential at a point in a gravitational field?
Definition
 The gravitational potential at a point in a gravitational field is the work done against the field (or energy change) per unit mass [image] when an object is moved from infinity to the point [image]
Term
 State the relationship between the gravitational potential energy, Ep, and the gravitational potential, V, for a body of mass m placed in a gravitational field
Definition
 The relationship between them is that Ep equals the product of the mass m and the gravitational potential V or Graviational potential is gravitational potential energy per unit mass (or per kg)
Supporting users have an ad free experience!