Chapter 20, Problem 51A

The diameter of a fire hose varies with the flow rate of water inside. The hose may be relatively narrow, and at another time puffed up like a fat snake. In which case is water flowing fast, and when is water hardly flowing at all?

To determine

To find: The case in which water will flow faster and slower.

Answer to Problem 51A

Water flows faster in the narrow pipe and hardly flows when the hose diameter is bigger.

Explanation of Solution

Introduction:

According to Boyle’s law, the pressure is inversely proportional to the volume.

When water flows in the narrow pipe, then water pressure inside is lesser and it makes the water flow faster in the pipe. But, when water is at rest in the pipe or flows very slowly, then the pressure will build up, the speed of flowing decreases, hose pipe diameter increases.

Conclusion:

Thus, water flows faster in the narrow pipe and hardly flows when the hose diameter is bigger.