The segment of river shown has a rectangular cross-section, with width 50 ft. The river bed is at angle ?=100 from horizontal. The average velocity is 2 ft/s at the upstream end (point 1), and 3 ft/s at the downstream end .The vertical depths are as follows: ?Z1=4 ft and ?Z2 = 3.5 ft. Fresh water is flowing at a temperature of 600F.
Find:
a) mass flow rate at sections 1 and 2 (m=densityV*A) *note it is the dot product of the velocity and area*
b) calculate rate of change of water mass in the segment . interpret the answer