1. An object is undergoing SHM with an amplitude 0.320 m. It goes through 20 cycles of oscillation in 18 seconds. At t = 0 the object is at x = 0.320 m and is instantaneously at rest. Calculate the time it takes the object to go from x = 0.320 m to x = 0.160 m for the first time. 2. A 1.50-kg mass on a spring has displacement as a function of time given by x(t) = 7.40cm * cos [(4.16 rad)t-2.42] Find (a) the time for one complete vibration; (b) the force constant of the spring; (c) the maximum speed of the mass.