11. A block whose mass m is 650 g is fastened to a spring whose spring constant k is 65 N/m. The block is pulled a distance x = 11 cm from its equilibrium position at x = 0 on a frictionless surface and released from rest at t = 0. What is the angular frequency of the resulting oscillation motion? (A) 8 rad/s (B) 9 rad/s (C) 10 rad/s (D) 11 rad/s (E) 12 rad/s .