Hot air enters a rectangular duct (20-cm-wide, 25-cm-high, and 5-m-long) at 100 kPa and 60 o C at an average velocity of 5 m/s. While air flows through the duct, it gets cool down (loses energy) so that air leaves the duct at 54 o C. Determine the rate of heat loss from the air under steady condition.

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.