A pipe carrying 20°C water has a diameter of 3.9 cm. Estimate the maximum flow speed if the flow must be streamline. (The density of water is 1.00 ✕ 10^3 kg/m3.) ans in cm/s

Answer 1

I am not going to try to do this for you. Your text has likely different caalculations for crritical Reynolds number and water viscosity than mine.

Look in your text for dritical transition Reynolds number from laminar to turbulent flow in pipe.
Calculate that number using your text values for Re, viscosity versus temp (in degrees K likely add 273 for 293 K) and diameter of 0.039 meter
solve for v

https://en.wikipedia.org/wiki/Reynolds_number