3.7. Fields
Force field def.?
- a region in which a body experiences a non-contact force
- consists of vectors
~gravitational fields~
Define field lines?
Diff ways of creating a force field?
- by the interaction of masses → gravitational field
- by the interaction of static charges → electric field
- by the interaction of moving charges → electric field
Gravity def.?
- a universal attractive force acting between all matter
- its magnitude can be calculated using:
where G = gravitational constant and:
What does Newton’s law of gravitation assume?
~the grav. force between any two point objects is:
- say instead = proportional to the PRODUCT of their masses
⇒ hence the equation
,Equation of F being an inverse square law?
What does g stand for?
- gravitational field strength
‘g’ def.?
- g = F/m only applies to small masses placed in a gravitational field of a large mass →
otherwise:
How can Newton’s law of gravitation be used to determine g of a grav. field?
- the grav. field strength at any point in the field of a planet/any spherical mass
⇒ so for radial fields ONLY
- how to derive it:
(remember: r is radial distance from the CENTRE of the spherical mass)
Radial field def.?
- field lines are directed towards the centre of a sphere
→ the magnitude of g decreases with increasing radial distance away from the large body
Uniform field def.?
- g is same in magnitude and direction throughout the field
, Derive g inside a planet?
Force field def.?
- a region in which a body experiences a non-contact force
- consists of vectors
~gravitational fields~
Define field lines?
Diff ways of creating a force field?
- by the interaction of masses → gravitational field
- by the interaction of static charges → electric field
- by the interaction of moving charges → electric field
Gravity def.?
- a universal attractive force acting between all matter
- its magnitude can be calculated using:
where G = gravitational constant and:
What does Newton’s law of gravitation assume?
~the grav. force between any two point objects is:
- say instead = proportional to the PRODUCT of their masses
⇒ hence the equation
,Equation of F being an inverse square law?
What does g stand for?
- gravitational field strength
‘g’ def.?
- g = F/m only applies to small masses placed in a gravitational field of a large mass →
otherwise:
How can Newton’s law of gravitation be used to determine g of a grav. field?
- the grav. field strength at any point in the field of a planet/any spherical mass
⇒ so for radial fields ONLY
- how to derive it:
(remember: r is radial distance from the CENTRE of the spherical mass)
Radial field def.?
- field lines are directed towards the centre of a sphere
→ the magnitude of g decreases with increasing radial distance away from the large body
Uniform field def.?
- g is same in magnitude and direction throughout the field
, Derive g inside a planet?
