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twiztidmxcn
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Homework Statement
Consider y''(t)+(k/m)*y = 0 for simple harmonic oscillation
A) Under what conditions on Beta is y(t)=cos(Beta*t) a solution?
B) What is the period of this solution?
C) Sketch the solution curve in the yv-plane associated with this solution (Hint: y^2 + (v/Beta)^2)
For A, I had:
dy/dt = v
dv/dt = -(k/m)*y
Found y' and y''
y'(t) = -Beta*sin(Beta*t) y''(t)=-Beta^2*cos(Beta*t)
Plugged those into the given equation and found Beta = +/- sqrt(k/m)
y(t) = cos (+/-sqrt(k/m)*t) -> answers for A
For B, I found the period to be T = 2*pi / Beta
For C, I found that y^2 + (v/Beta)^2 = cos^2(Beta*t) + Beta^2*sin^2(Beta*t)/Beta^2
My problem now is drawing this. I think, from remembering equations of shapes, that this is an ellipse, stretching in the v direction.
I am not sure, but I think the max and min points of the ellipse are:
y = 0, v = +/- sqrt(k/m)
v = 0, y = +/- 1
I also think that the direction of the field is counter-clockwise.
I don't know if part B and C were done totally right and am a bit confused about finding the direction of the phase field/solution.
-twiztidmxcn