Water flows through a 1-cm diameter pipe connected to a 1/2-cm diameter pipe. compared to the speed of the water in the 1-cm pipe, the speed in the 1/2-cm pipe is:

The speed of water in pipe is given by: V=0.408(Q/D^2) V=speed Q=flow rate D=diameter of pipe Hence, the speed of the water is inversely proportional to square of diameter If the speed of water through 1-cm diameter is V Then, speed of water through 0.5 cm diameter is =V/[(1/2)^2)] =V/(1/4) =4V Hence, compared to the speed of water in 1 cm pipe, the speed in the 1/2 cm pipe is four times.

Carbon is the most used and important atom among all that exist.

Explanation:

Carbon atom is special because it can form total of four chemical bonds with other atoms. Also carbon atom has very perfect size that is very right to fit comfortably as being the parts or base of very large molecules.Hydrocarbons are the base of every fuel used today and even carbon dioxide includes carbon within which our life is dependent.