Problem 26. Two infinite parallel plates a distance L apart are filled with an in compressible fluid. The lower plate is stationary and the upper plate oscillates in the x-direction

with a frequency w and an amplitude in the plate velocity of U as indicated in the figure below. c_{1}=R e, c_{2}=\omega L / U c_{1}=R e, c_{2}=U / L c_{1}=1 / R e, c_{2}=\omega L / U c_{1}=1 / R e, c_{2}=U / L \text { None of these }