There is a shell-and-tube heat exchanger (1-20) that uses hot water from the tube side to heat oil flowing from the shell side. Each copper tube has an internal diameter of 20 mm, an external diameter of 24 mm, and a length of 3 m per pass. Water enters each tube at 87C, at a rate of 0.2 kg/s, and exits at 27C. The oil is heated from 7C to 37C. a) Use the Tml method and calculate the heat transfer coefficient on the shell side. b) Repeat the problem using the NTU method.