Knowledge that special relativity deals with motion in inertial (non-accelerating) frames of reference, and that general relativity deals with motion in non-inertial (accelerating) frames of reference.
Statement of the equivalence principle (that it is not possible to distinguish between the effects on an observer of a uniform gravitational field and of a constant acceleration), and knowledge of its consequences.
Consideration of spacetime as a unified representation of three dimensions of space and one dimension of time.
Knowledge that general relativity leads to the interpretation that mass curves spacetime, and that gravity arises from the curvature of spacetime.
Knowledge that light or a freely moving object follows a geodesic (the path with the shortest distance between two points) in spacetime.
Representation of world lines for objects which are stationary, moving with constant velocity, and accelerating.
Knowledge that the escape velocity from the event horizon of a black hole is equal to the speed of light.
Knowledge that, from the perspective of a distant observer, time appears to be frozen at the event horizon of a black hole.
Knowledge that the Schwarzschild radius of a black hole is the distance from its centre (singularity) to its event horizon.
Use of an appropriate relationship to solve problems relating to the Schwarzschild radius of a black hole.