In a shell-and-tube heat exchanger, the overall and individual heat transfer coefficients are \(U=\)

\(300 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}, h_{i}=1000 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\), and \(h_{o}=500 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\). Both the shell-side and the tube-side fluids are liquids, and no change of phase occurs. The flow of both fluids is turbulent.

a. Estimate the new value of \(U\) if the flowrate of the shell-side fluid is decreased by \(20 \%\).

b. Estimate the new value of \(U\) if the flowrate of the tube-side fluid is decreased by \(20 \%\).

c. Estimate the new value of \(U\) when both situations in Parts (a) and (b) exist.