A uniform bar, of mass M, with seven evenly spaced holes is held by sliding the bar over a horizontal peg through one of the seven holes. The peg passes through hole C, and a cylin- der hangs from a hook placed through hole B as shown above. The mass of the bar is equal to the mass of the cylinder, and the location of the center of mass of the bar is at the center of hole D. In this configuration, the bar-cylinder system remains motionless but is free to rotate around the peg in hole C. Frictional forces acting on the bar are negligible. In a clear, coherent paragraph-length response that may also contain equations, explain why the bar does not rotate in this configuration.

A uniform bar, of mass M, with seven evenly spaced holes is held by sliding the bar over a horizontal peg through one of the seven holes. The peg passes through hole C, and a cylin- der hangs from a hook placed through hole B as shown above. The mass of the bar is equal to the mass of the cylinder, and the location of the center of mass of the bar is at the center of hole D. In this configuration, the bar-cylinder system remains motionless but is free to rotate around the peg in hole C. Frictional forces acting on the bar are negligible. In a clear, coherent paragraph-length response that may also contain equations, explain why the bar does not rotate in this configuration.