05 - IFSTA Chapter 05 Flashcards
How much does a cubic foot of fresh water weigh?
62.4lbs
When converted to steam, water expands by approximately how many times?
1,700
A 1 inch column of water, 1 foot high exerts what pressure?
0.434
What is the first principle of pressure?
Fluid pressure is perpendicular to any surface on which it acts
What is the second principle of pressure?
Fluid pressure at a point in fluid at rest is the same intensity in all directions
What is the third principal of pressure?
Pressure applied to a confined fluid is transmitted equally in all directions
What is the fourth principal of pressure?
The pressure of a liquid in an open vessel is proportional to its depth
What is the fifth principal of pressure?
The pressure of a liquid in an open vesssel is proportional to the density of the liquid
What is the sixth principal of pressure
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel
What is atmospheric pressure at sea level?
14.7
How many feet will 1 psi raise a one square inch column of water?
2.304
Above sea level, atmospheric pressure decreases by aproximately how much psi for every 1,000ft?
0.5 psi
The friction loss in older hose can be as much as what percent?
50%
What is the first principle of friction loss?
If all other conditions are the same, friction loss varies directly with the length of the hose or pipe
(Double the length, double the FL)
What is the second principle of friction loss?
When hoses are the same size, friction loss varies approximately with the square of the increase in the velocity of the flow
What is the third principal of friction loss
For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose
What is the fourth prinicpal of friction loss
For a given velocity, friction loss is approximately the same, regardless of the pressure of the water
What pressure is required to reduce the volume of water by 1 percent?
30,000 psi
What are the most common type of valves used on most public water distribution systems?
Non-indicating
Which of the following cannot affect friction loss in fire hose
Weather
Water is considered to be:
incompressible
Water can be used to smother fires in what kind of combustible liquids?
Those with a specific gravity higher than 1
What principle of water makes it somewhat difficult to soak into dense material?
Its high surface tension
The term force is a simple measure of weight that is expressed in what unit of measurement:
pounds and newtons