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Lizwi
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Homework Statement
Please help me solve this differential equation: This is mass attached to a spring, we have
F= ma= -kx -bv + Fext where k and v are spring constant and velocity respectively and Fext is an additional external force.
Homework Equations
I know how to solve nonhomogeneous differential equations mathematically but on the right of the above equation is not a function so I stuck.
The Attempt at a Solution
I tried this way:
writing the above as differential equation I have
md2x/dt2 + bdx/dt + kx = Fext
for homogeneous part md2x/dt2 + bdx/dt + kx=0
the solution I assumed is x(t) =Aept
the first derivative of the assumed solution is x'(t)= Apept and the second derivative is x''(t)= Ap2ept
substituting all these x(t), x'(t) and x''(t) to the differential equation and divide by
Aept I get:
mp2 + bp+k=0
for inhomogeneous part I don't know ho to handle this right hand side Fext. Please help me.
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