I keep getting this question wrong.

Consider the following figure. A thread has one end tied to a wall, extends across a small fixed pulley, and the other end is tied to a hanging object. M The total length of the thread is L = 10.0 m, the mass of the thread is m = 9.00 g, the mass of the hanging object is M = 7.50 kg, and the pulley is a fixed a distance d = 8.00 m from the wall. You pluck the thread between the wall and the pulley and it starts to vibrate. What is the fundamental frequency (in Hz) of its vibration? 14.29 X Note that because the thread is draped over the small pulley only the length d = 8.00 m between the wall and the pulley will vibrate. Hz Need Help? Read It