7.1 - Gravitational Fields Flashcards
What is a force field?
Any region of space where a body will experience a non-contact force.
What force do static or moving charged particles experience?
Electric field force
What force do moving charged particles experience?
Magnetic field force
What force do particles with mass experience?
Gravitational field force
What is a gravitational field defined as?
A region of space where a mass experiences a force due to the gravitational attraction of another mass.
What direction does a gravitational field act in?
ALWAYS towards the centre of the mass, radially inwards (cannot be repulsive).
What is gravitational field strength?
The force per unit mass on an object in a gravitational field. (N/kg
What is the gravitational field strength on Earth?
g = 9.81 N/kg
What 2 factors effect the gravitational field strength at the surface of a planet?
- The radius
- The mass
What is a uniform field in a gravitational field?
A region (ie surface of Earth) where the field strength is the same at all points. This is represented by lines that are equidistant and parallel.
What is a point mass?
A mass where size and dimensions can be neglected. (makes questions more simple)
What is Newton’s law of gravitation? (written)
The gravitational force between 2 point masses is proportional to the product of the masses and inversely proportional to the square of their separation.
Is gravitational field strength a vector or scalar quantity?
Vector
(direction towards centre of mass)
When distance to object < radius of larger mass, what is the relationship between g and r?
g ∝ r.
When the distance to object > radius of larger mass, what is the relationship between g and r?
g ∝ 1/r²
