ASSIGNMENT QUESTION 3 PART 2

PLEASE NOTE THAT I ONLY REQUIRE THE ANSWER FOR PART 2 OF THE QUESTION BELOW. ALSO THAT I HAVE BEEN GIVEN AN ANSWER OF 87.8 rad/s FOR PART 2, BUT WITH NO WORKINGS OUT, WHICH I AM REQUESTING FROM YOU. HOPE YOU CAN HELP.
I HAVE INCLUDED AN ATTACHMENT BELOW OF THE QUESTION, IN CASE YOU DO NOT GET THE COMPLETE QUESTION BELOW.

Question 3

Fig. Q3 shows a rigid light beam which is hinged at O to a wall. The beam carries a point mass of m at the free end. The beam is connected at its mid-point to a spring (stiffness k) which is also connected to a support that moves with a vertical motion y = Y sinwt. A damper (coefficient c) connects the mid-point of the beam to a fixed support.
                            


(ii)Determine the maximum value for w if the amplitude ratio of the x displacement  (i.e. X)  to Y is not to exceed 10%.    

Take m =  2 kg;   k = 6.25 kN/m;  c = 45 Ns/m.       
                                     (Answer:  87.8 rad/s)

Fig. Q3