In SHM (simple harmonic motion), the general equations for position, velocity, and acceleration are:
x(t) = A cos(ωt + θo)
v(t) | = -Aω sin(ωt + θo) |
a(t) | = -Aω2 cos(ωt + θo) |
The phase angle θo is determined by the initial position and initial velocity.
The angular frequency is determined by the system. For an object of mass m oscillating on a spring of spring constant k the angular frequency is given by:
ω2 | = |
|
Whatever is multiplying the sine or cosine represents the maximum value of the quantity. Thus:
xmax = A
vmax = Aω
amax = Aω2
Graphing the position, velocity, and acceleration allows us to see some of the general features of simple harmonic motion:
The first set of graphs is for an angular frequency ω = 1 rad/s. The second set of graphs is for ω = 0.6 rad/s. This change of ω is accomplished either by decreasing the spring constant or by increasing the mass. Which change did we make in this case?