#5.4.1a
gravitational fields are due to objects having mass
#5.4.1b
modelling the mass of a spherical object as a point mass at its centre
#5.4.1c
gravitational field lines to map gravitational fields
#5.4.1d
gravitational field strength;
\(g = \dfrac{F}{m} \)
#5.4.1e
the concept of gravitational fields as being one of a number of forms of field giving rise to a force.
Learners will be expected to link this with section 6.2