Scientific must be supported by observations and results from many investigations and are not absolute.

theories

Explanation:

A scientific theory is a specific type of theory used in the scientific method.  A scientific theory is an unproven concept, it is a hypothesis. That is, a theory refers to a concept that needs to be explained and tested through a series of experiments. In other words, we can say that scientific theories must be supported by observations and results of many investigations and are not absolute.

we need the questions , i may then you.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.