Ch 5 Principles Of Water

Question 1

Water is considered to be virtually ________ and it’s weight varies at different temperatures.

Answer 1

Incompressible

P. 167

Question 2

For fire protect purposes ordinary fresh water is considered to weigh _____ or _____ lb a gallon.

Answer 2

62. 4 lbs per cubic foot
63. 3 lbs a gallon

P. 167

Question 3

At 212 F water converted to steam occupies approximately _______ times it’s original volume.

Answer 3

1700

P. 169

Question 4

The weight of water in a 1 square inch column of water 1 ft high equals.

The same column has a pressure of ______ psi

It would take a column with the height of _____ to have a pressure of 1 psi.

Answer 4

.434lbs
.434 psi
2.304 feet

P. 171

Question 5

Waters first principle

Answer 5

Fluid pressure is perpendicular to any surface on which it acts.
Fluid at rest in a container with flat sides will have the same pressure on either side or bottom of the container.
Example is a square swimming pool with a depth of 4 ft. It will have the same pressure on all sides.

P. 172

Question 6

Second principle

Answer 6

Fluid pressure at a point in fluid at rest is the same intensity in all directions.

Pressure testing.

Example is either hydrostatic testing or think of a water line with a hydrant and it not being in use. Static pressure.

P. 172

Question 7

Third principle

Answer 7

Pressure applied to a confined fluid is transmitted equally in all directions.

Water in a container that is being forced down with an object with create pressure in the container. The pressure inside will be the same as long as there is no elevation.

P. 172

Question 8

Forth principle

Answer 8

The pressure of a liquid in an open vessel is proportional to its depth.

A container that is 1 ft tall will have different pressure than a container at 2 for tall. The weight of water effect the pressure is containers of different depths.

Example is a body the deeper body of water will have the greatest pressure

P. 173

Question 9

Fifth principle

Answer 9

The pressure of a liquid in an open vessel is proportional to the density of the liquid.

Mercury weighs the same in a 1 inch container as water does in a 13.55 inch container

P. 173

Question 10

Sixth principle

Answer 10

The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel.

Whatever shape the container is the water will be that shape also.

P. 174

Question 11

Atmospheric pressure at sea level

Answer 11

14.7

P. 174

Question 12

A pressure of 1 psi makes mercury in a column raise to ______ inches

At sea level the column of mercury is 2.04 x14.7 ( atmospheric pressure) which equals.

Answer 12

2. 04 inches
3. 9 inches

P. 174

Question 13

Any pressure less than atmospheric pressure is called _______ and absolute zero pressure is called _________.

Answer 13

Vacuum

Perfect vacuum

P. 175

Question 14

_____ refers to the centerline of the pump or the bottom of a static water supply source above or below ground level.

Answer 14

Elevation

P. 176

Question 15

Above sea level atmospheric pressure decreases approximately ______ for every 1000 ft.

Answer 15

.5 psi

P. 176

Question 16

Loss of pressure created by the turbulence of water moving against the interior walls of the hose or pipe.

Answer 16

Friction loss

P. 177

Question 17

Friction loss in older hose may be as much as _____ greater than that of newer hose.

Answer 17

50%

P. 177

Question 18

Coefficient of friction is

Answer 18

Rough inner surface of pipe

P. 177

Question 19

With water being incompressible a pressure of ______ is required to reduce its volume ____ percent.

Answer 19

30000
1%

P. 179

Question 20

There are practical limits to the velocity at which a stream can travel. If the velocity is increased beyond this point the friction will become so great that the entire system is agitated by resistance which causes turbulence known as___________.

Answer 20

Critical velocity

Larger hoses or more hoses will decrease this.

P. 181