The electric field in a certain region of earth's atmosphere is directed vertically down. at an altitude of 247 m the field has magnitude 52.6 n/c; at an altitude of 152 m, the magnitude is 78.3 n/c. find the net amount of charge contained in a cube 95 m on edge, with horizontal faces at altitudes of 152 m and 247 m.

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.