Ahypothetical metal alloy has a grain diameter of 2.4 × 10−2 mm. after a heat treatment at 575°c for 500 min, the grain diameter has increased to 5.6 × 10−2 mm. compute the time required for a specimen of this same material (i. e., d0 = 2.4 × 10−2 mm) to achieve a grain diameter of 5.5 × 10−2 mm while being heated at 575°c. assume the n grain diameter exponent has a value of 2.2.