Water at 54F is heated by passing it through 0.75-in.- internal-diameter thin-walled copper tubes. Heat is supplied to the water by steam that condenses outside the copper tubes at 250F. If water is to be heated to 140F at a rate of 0.7 lbm/s, determine the length of the copper tube that needs to be used. Assume the entire copper tube to be at the steam temperature of 250F