object mass 5g hangs cord around pulley length cord between point

An object with a mass of 5g hangs from a cord around a pulley.? The length of the cord between point P and the pulley L=2.0m a) when the vibrator is set to a frequency of 150 Hz, a standing wave with 6 loops is formed. What must be the linear mass density of the cord? b) How many loops (if any) will result if m is changed to 45 kg? c)how many loops (if any) will result if m is changed to 10 kg?