Simple Harmonic Motion Flashcards
Periodic Motion
a motion which repeats after a finite amount of time
equation that proves when a motion is periodic??
x (t + T) = x(t)
same with v instead of x (velocity vs position)
if T is time period and t is actual time spent, means will return to same position and velocity regularly/PERIODICALLY!! <3
oscillation
complete back and forth
frequency!! freak quency
oscillations per time period, given by
f = 1/T
measured in s ^-1 or Hz, 1 Hz = one oscillation /second
T
period/time to complete one oscillation
general notes on sin function
begins at origin, 0
period of 2pi unless changed
amplitude of 1 unless changed
up first
o with line through it would be 3pi/4
general nots on cosine
begins at y = 1
period of 2pi unless changed
amplitude of 1 unless changed
down first
o with line through it would be 0
manipulation of cosine and sin
[A] cos/sin(x) - og amplitude would be one, this is multiplied by A, if A> 1 stretch, <1 compression. If A is negative, graph is flipped along the x axis!
cos/sin ([n] x) - horizontal stretch/compression, og wavelength is 2pi, if any number before x etc, divide 2pi by that to get new wavelength!! ex. sin (2x), 2pi/2 = pi therefore new wavelength is pi. IF n is -, technically flip over the y axis but same results as flip over x
cos/sin (x +/- g) - shift left or right by g units, COUNTERINTUITIV`E if (x +…) shift to the left! if (x - ….) shift to the right
cos/sin (x) + h - shift whole ass graph up or down by h! actually makes sense, + h shift up so midpoint is 0 + h, if - h shift down so midpoint is 0 - h
relationship between sin and cos, how to transform into the other
sin (theta + pi/2) = cos(theta)
cos (theta - pi/2) = sin (theta)
what the heck does multivalued mean???
multiple values of theta/ angle inserted into sin/cos equation will give the same results
IMPORTANT equation for simple harmonic motion!!!
x(t) = A cos (wt + [o with line down center])
A = amplitude
w = angular frequency (calculated by 2pif or 2pi/T) f is frequency i think confirm this
[o with line down middle] = phase constant (determined by initial position and velocity of graph, related to position on the unit circle
how to calculate fancy w???
2pi/T OR 2pif where T is the period and f is frequency because remember frequency = 1/T
units = radians
how to determine phase constant
fancy o with line (phase constant) = cos^-1 ([x(0)] / A)
x(0) is y position at x = 0
how to find velocity of shm
take the derivative of position function!!!
v(t) = dx(t)/d(t) = d/dt (Acos (wt + funky circle)
v(t) = -(wA) sin (wt + funky circle)
calculate max velocity???
vmax = wA OR (2pi/T x A)