Problem 12.39 | A classic problem in vibrations is the single degree-of-freedom damped vibration problem in which the one-dimensional amplitude of an oscillating particle is described by: x(t) = Aeat cos t where A is the initial amplitude and a and describe the strength of the decay and the frequency of oscillation, respectively. For A = 0.1 m, a = 0.1 s and = 0.2 s1, at what time does the velocity first go to zero? What is the value of the acceleration at this instant?