If an rc circuit supplied with 20 vdc and the circuit is in it's second time constant, how much voltage is present across the capacitor?

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i. d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.

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.

Natural gas (95 percent methane and 5 percent ethane by volume) flows through a 90 cm diameter pipeline with a velocity of 3 m/s. the pressure in the pipeline is 700 kpa, and the temperature is 15°c. calculate: (a) the mass and volumetric flow rates in this pipe.