Problem #4: Air at 100 kPa and 300 K flows steadily through a square duct with side length of 0.5 m. The air enters with a uniform speed of 5 m/s. An electric surface heating element is attached to the left side of the duct, resulting in a non-uniform temperature profile at the duct exit: T(x) = 320K+ [20K].e() Assuming the exit velocity is also uniform, determine: a) the exit velocity of the air, b) the power input to the heater. You may model air as an ideal gas with constant specific heat (R = 0.287 kJ/kg-K, C = 1 kJ/kg-K). Inlet: Air, 100 kPa, 300 K, 5 m/s S = 0.5 m Electric Surface Heater y N HVAC Duct Outlet: Air, T(x) given, Vexit = ?