Atransmission shaft, rotating at 500 rpm drives a milling machine which requires 3.75 kw at 750 rpm. a 300 mm diameter cast iron pulley is mounted on the transmission shaft. a preliminary design proposes using a belt of 4.75 mm thickness, which has a density of 970 kg/m². the allowable stress is 2 mpa. two pulleys rotate in opposite directions and the centre distance of the shafts is 750 mm. the co efficient of friction is 0.3 for both the pulleys. determine the width of the belt.