Terms

Torsional Oscillator
The oscillation of any object suspended by a wire and rotating about the axis of
the wire.

Pendulum
The classic pendulum consists of a particle suspended from a light cord. When
the particle is pulled to one side and released, it swings back past the
equilibrium point and oscillates between two maximum angular displacements.

Damping force
A force proportional to the velocity of the object that causes it to slow down.

Resonance
The phenomena in which a driving force causes a rapid increase in the
amplitude of oscillation of a
system.

Resonant Frequency
The frequency at which a driving force will produce resonance in a given
oscillating system.
Formulae
Equation for the torque felt in a torsional oscillator
 τ =  κσ 
Equation for angular displacement of a torsional oscillator
 θ = θ_{m}cos(σt) 
Equation for the period of a torsional oscillator
 T = 2Π 
Equation for the angular frequency of a torsional oscillator
 σ = 
Equation for the force felt by a pendulum
 F = mg sinθ 
Approximation of the force felt by a pendulum
 F  ()x 
Equation for the period of a pendulum
 T = 2Π 
Differential equation describing damped motion
 kx + b + m = 0 
Equation for the displacement of a damped system
 x = x_{m}e^{}cos(σ^{â≤}t) 
Equation for the angular frequency of a damped system
 σ^{â≤} = 