TAP 302- 4: A language to describe oscillations
A summary of terms and relationships between them, shown on a diagram.
Language to describe oscillations
Sinusoidal oscillation
+A
Phasor picture
s = A sin t
amplitude A
A
angle t
0
time t
–A
periodic time T
phase changes by 2
f turns per 2 radian
second
per turn
 = 2f radian per second
Periodic time T, frequency f, angular frequency :
f = 1/T unit of frequency Hz
 = 2f
Equation of sinusoidal oscillation:
s = A sin 2ft
s = A sin t
Phase difference /2
s = A sin 2ft
s = 0 when t = 0
sand falling from a swinging pendulum leaves
a trace of its motion on a moving track
s = A cos 2ft
s = A when t = 0
t=0
Practical advice
This diagram is reproduced here so that you can talk through it, or adapt it to
your own purposes.
External reference
This activity is taken from Advancing Physics chapter 10, 60O