The linear density of a rod of length 4 m is given by rho(x) measured in kilograms per meter, where x is measured in meters from one end of the rod. rho(x) = 10 + 2 sqrt(x) find the total mass m of the rod.

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.