Apassenger jet is flying at an altitude of 12 000 m where the pressure is 200 hpa and the outside temperature is -47°c. to maintain comfort for the passengers, the air must be at 700 hpa and 18°c in the cabin. does the air need to be heated or cooled to achieve this? show your reasoning. hint: when air is compressed without adding or subtracting energy (without being heated or cooled) it maintains its potential temperature.

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

Light traveling in water, nwater = 1.33, strikes a plastic block at an angle of incidence of 51.4°; part of the beam is reflected and part is refracted. if the index of refraction of the plastic is 2.0, what is the angle made by the reflected and refracted beams?

8.29 two streams containing pyridine and acetic acid at 25°c are mixed and fed into a heat exchanger. due to the heat-of-mixing effect, it is desired to reduce the temperature after mixing to 25°c using a stream of chilled ethylene glycol as indicated in the diagram. calculate the mass flow rate of ethylene glycol needed. the heat capacity of ethylene glycol at these conditions is approximately 2.8 kj/(kg k), and the enthalpy change of mixing (δmixh) is given below.