A barbell is loaded with two 20 kg plates on its right side and two 20 kg plates on its left side. The barbell is 2.2 m long, and its unloaded mass is 20 kg. The two 20 kg plates on the right side are locked in place at 35 cm and 40 cm from the right end of the bar. The two 20 kg plates on the left side have slipped. One is 30 cm from the left end of the bar, and the other is 20 cm from the left end of the bar.
Where is the center of gravity of this barbell with the four plates? (Make sure you specify this distance relative to your axis of rotation - i.e. the left end of the bar, the right end of the bar, or the center of the bar)