EE 241 – Prelab #311. Derive (from the integral formula for RMS given in narrative 3) a relationship for Vrms in terms of Vp for a sinusoid. Let the sinusoid v(t) be expressed as: v(t) =VP cos (ωt + θ) where the peak voltage VP is nonnegative, the phase angle θ is real, and the frequency ω is positive. (To use the formula for Vrms you must know how ω and the period T are related.)

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2