Abarbell is 1.5 m long. three weights, each of mass 20 kg, are hung on the left and two weights of the same mass, on the right. the width of each weight is 4 cm and each group of weights is placed 4 cm from the ends. where is the center of mass of the barbell as measured from the mid-point, m, of the bar? the bar is of uniform mass and has mass 5 kg, and the retaining collars are of negligible mass. take to the right as positive.