Two identical uniform bars are welded together at a right angle and are pivoted about a horizontal axis through point O as shown. Determine the critical driving frequency wc of the block B which will result in excessively large oscillations of the assembly. The mass of the welded assembly is m = 27 kg, the length lis 525 mm, and the spring constant kis 616 N/m. 1/2 1/2 0 B Xo = b sin et =b Answer: Wc = i rad/s