Air enters the duct of an air-conditioning system at 42∘C and 66 kPa at a velocity of 2 m/s. Mass flow rate is 2 kg/s. Heat is transferred to the air in the duct from the surroundings. There is also an electric power input of 25 kW. The air exits the duct at 57 ∘C. Determine (a) the heat transfer rate to the duct, (b) density of the air entering the duct, (c) the volume flow rate at the inlet, and (d) diameter of the duct.[ R=0.287kPa *m^3/kg* K, :Cp=1.005 kJ/kg* C

Acapacitor is storing energy of 3 joules with a voltage of 50 volts across its terminals. a second identical capacitor of the same value is storing energy of 1 joule. what is the voltage across the terminals of the second capacitor?

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c

Four 5-gram blocks of metal are sitting out in the sun and absorb the same amount of heat energy. use the following specific heat capacity data to determine which block will increase its temperature the most.