Using a spreadsheet, emulate a diode radio by: 1. Computing an AM signal
2. Rectifying the signal in software
3. Filtering (using the low pass techniques from the earlier modules) to recover the envelope
4. Show, using a quantitative example, why phase coherence between the carrier and the LO is not required in a superheterodyne receiver.

For a gate width of 2 m into the paper, determine the force required to hold the gate abc at its location.

Natural gas (95 percent methane and 5 percent ethane by volume) flows through a 90 cm diameter pipeline with a velocity of 3 m/s. the pressure in the pipeline is 700 kpa, and the temperature is 15°c. calculate: (a) the mass and volumetric flow rates in this pipe.

Steam in a heating system flows through tubes whose outer radius is 2.5 cm and whose walls are maintained at a temperature of 180 °c . circular aluminum alloy 2024-t6 fins ( k= 186 wm. k) of outer radius 3 cm and constant thickness 1 mm are attached to the tube. the space between the fins is 3 mm and thus there are 250 fins per meter of tube length. heat is transferred to the surrounding air at too-25 °c, with a heat transfer coefficient of 40 w/m2. k. manufacturer a claims that this system is rated at 3.5 kw per meter of tube length. if the fins are an integral part of the steam tube, find the heat transfer rate in kw for a 1-m length of tube. is manufacturer a's claim valid? compare the heat transfer rate from 1 meter of tube length if there are no fins.