The following mass-and-spring system has stiffness matrix K. The system is set in motion from rest (x4(0) = x5'(0) = 0) in its equilibrium position (x4 (0) = x5(0) = 0) with the given external forces F4(t)=0 and F,(t) = 1512 cos 5t acting on the masses m, and m,, respectively. Find the resulting motion of the system and describe it as a superposition of oscillations at three different frequencies. K k | my my 3' . - (k1 +ko) Ky |&1 x, ko = (ka2 +k3) my=1,my=2k=1,ky=2,ky=2 The two masses oscillate in opposite directions with equal amplitudes. The two masses oscillate in the same direction with equal amplitudes. The two masses oscillate in the same direction, where the amplitude of m, is times the amplitude of m,. (Simplify your answer.) The two masses oscillate in opposite directions, where the amplitude of m, is 2 times the amplitude of m,. (Simplify your answer.) Describe the mode of oscillation for m. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. X The two masses oscillate in opposite directions with equal amplitudes. The two masses oscillate in the same direction, where the amplitude of m4 is times the amplitude of m,. (Simplify your answer.) The two masses move linearly, staying a fixed distance apart. 1 The two masses oscillate in opposite directions, where the amplitude of m, is " times the amplitude of m,. (Simplify your answer.) The two masses oscillate in the same direction with equal amplitudes