To warm up some milk for a baby, a mother pours milk into a thin-walled glass whose diameter is 6-cm. the height of the milk in the glass is 7-cm. she then places the glass into a large pan filled with hot water at 60°c. the milk is stirred constantly, coefficient between water and the glass is 120w/m°c, determine how long it will take the milk to warm from 3°c to 38°c. take the properties of the milk same as those of water. can the milk in this case be treated as a lumped parameter system? why?