The time required for one complete up/down cycle of a wave.
What is the period?
This is the rotational analog of mass for linear motion and roughly speaking it quantifies how hard it is to spin an object.
What is rotational inertia (or moment of inertia)?
The quantity that is conserved when the shape of a spinning object changes as long as there are no external torques.
What is angular momentum?
The ratio of the force the Earth exerts on the moon to the force the moon exerts on the Earth.
What is one?
Hooke's Law is defined by this relationship.
What is the force is directly proportional to the displacement? (F = kx)
The displacement as a function of time for an object undergoing Simple Harmonic Motion is given by this mathematical function.
What is sine or cosine?