On a day when the temperature of the air is 20 C a factory siren indicating the end of a shift has a frequency of 80 Hz. What is the speed of sound on this day?

An ideal otto cycle has a compression ratio of 8. at the beginning of the compression process, air is at 95 kpa and 27°c, and 750 kj/kg of heat is transferred to air during the constant-volume heat-addition process. assuming constant specific heats at room temperature, determine (a) the pressure and temperature at the end of the heat-addition process, (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle. (4390 kpa, 1730 k; 423 kj/kg; 56.4%; 534 kpa)

Check the following equation for dimensional homogeneity: ⅆ mv=∫t1t2(f⁢cosθ)ⅆt where m is mass, v is velocity, f is force, θ is an angle, and t is time. check that each term in the equation has the following dimensions: [malbec] where you are to choose the coefficients a, b, c.

If you visited mount shasta city (elevation 900 m [3000 ft.]) and found the outside air temperature to be 27°c (81°f), what would be the air temperature at the summit of mount shasta (elevation 4200 m [14,000 ft.]) at that moment-assuming that the temperature conditions with altitude change at an average, or normal, lapse rate?