How Do You Approach Solving a Forced Wave Equation with Sinusoidal Terms?

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SUMMARY

The discussion focuses on solving the forced wave equation given by the formula \(\nu^2 \frac{\partial^2 \psi}{\partial x^2} = \frac{\partial^2 \psi}{\partial t^2} + a \frac{\partial \psi}{\partial t} - b \sin\left(\frac{\pi x}{L}\right) \cos\left(\frac{\pi \nu t}{L}\right)\). The boundary conditions are specified as \(\psi(0,t) = \psi(L,t) = \frac{\partial \psi(x,0)}{\partial t} = 0\) and the initial condition is \(\psi(x,0) = c \sin\left(\frac{\pi x}{L}\right)\). The user suggests using separation of variables for the homogeneous part and considers a trial function involving sinusoidal terms to address the forced component.

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Homework Statement


If a system satisfies the equation \nu^2 {\partial^2 \psi\over \partial x^2}={\partial^2 \psi\over \partial t^2}+a{\partial \psi\over \partial t}-b\sin\left({\pi x \over L}\right)\cos\left({\pi \nu t\over L}\right)
subjected to conditions: \psi(0,t)=\psi(L,t)={\partial \psi(x,0)\over \partial t}=0 and \psi(x,0)=c\sin\left({\pi x\over L}\right),

how might I solve this?
Thanks.

Homework Equations



As above.

The Attempt at a Solution



I can solve the equation \nu^2 {\partial^2 \psi\over \partial x^2}={\partial^2 \psi\over \partial t^2}+a{\partial \psi\over \partial t} by separation of variables. But I don't know how to deal with the b\sin\left({\pi x \over L}\right)\cos\left({\pi \nu t\over L}\right) term. Also, what is the "forced component" of \psi(x,t)?
 
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Laplace transform?
 
You might try a trial function of the form Phi (x,t) = K sin (pi x/L) cos (pi nu t/L)

From your post, I am not sure which constant terms nu, a, b, c, or L are known
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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