4.1. A liquid flows into a 5 m^3 tank at a flow rate of 3 kg/s and leaves at a rate of 2 kg/s. Initially, there is 1 m² of liquid in the tank.
(a) Classify the process as transient or steady-state
(b) Classify the process as batch, semi-batch, or continuous
(c) Write a mass balance for the process in terms of the general balance equation

Apiping systems consists of 6 m of 6-std type k and 12 m of 4-std type k, both drawn copper tubing. the system conveys ethylene glycol at a rate of 0.013 m3/s. the pressure drop across the system is to be calculated. there are two 90° elbows in the 6-in pipe, a reduction from the 6-in pipe to the 4-in pipe and four 90° elbows in the 4-in pipe. all fittings are soldered (same as flanged) and regular. the inlet and outlet of the system are at the same height.