(Solved): The 20-mm-diameter copper coil is used for a solar hot water heater. Water at an average temperatur ...

The 20-mm-diameter copper coil is used for a solar hot water heater. Water at an average temperature of \( T=50^{\circ} \mathrm{C} \) passes through the coil at \( 7.9 \) liter \( / \mathrm{min} \). At \( 50^{\circ} \mathrm{C} \) the water has the density of \( 988 \mathrm{~kg} / \mathrm{m}^{3} \) and kinematic viscosity of \( \nu=0.561\left(10^{-6}\right) \mathrm{m}^{2} / \mathrm{s} \). Take \( \varepsilon=0.03 \mathrm{~mm} \) for the coil. Suppose that \( L=350 \mathrm{~mm} \). Use the equation \( \frac{1}{\sqrt{f}}=-1.8 \log \left[\left(\frac{\varepsilon / D}{3.7}\right)^{1.11}+\frac{6.9}{\operatorname{Re}}\right] \) (Figure 1) Determine the major head loss that occurs within the coil. Neglect the length of each bend. Express your answer to three significant figures and include the appropriate units. Figure