PHEP 1 Flashcards
(53 cards)
Which of the four elements listed is the lighest per unit volume? A) Carbon B) Calcium C) Barium D) Aluminum
Calcium (see pg 2)
Which of the four elements listed is the lightest per atomic weight? A) Carbon B) Calcium C) Barium D) Aluminum
Carbon (see pg 2)
Water is? A) an element B) a compound C) a mixture D) a composition of hydrogen and helium
A compound
When two or more atoms combine chemically the particle thus formed is a? A) molecule B) nucleus C) mixture D) proton
molecule (smallest possible division of a compound)
A compound is formed when the atoms of two or more elements become? A) closely mixed together B) chemically bonded C) divided into simpler particles D) changed within their kernals
Chemically bonded
Our air (or atmosphere) is composed by volume of? A) 21% nitrogen and 79% oxygen B) 21% oxygen and 79% carbon C) 21% oxygen and 79% nitrogen D) 21% oxygen and 79%hydrogen
21% oxygen and 79 % nitrogen
Atmospheric pressure at sea level is normally considered to be approximately? A) 4.17 psi B) 7.14 psi C) 14.7 psi D) 17.4 psi
14.7 PSI
When molecules are tightly bound they are in a? A) Solid state B) Gaseous state C) Liquid state D) Suspended state
Solid state
Liquids offer a high resistance to any force tending to change their? A) fluidity B) volume C) specific gravity D) temperature
volume
A temperature reading of 59°F is equivalent to? A) 145.8° C B) 50.1° C C) 48.6° C D) 15° C
15°C C=5/9 x (F-32)/1 C=5/9 x (59-32)/1 C=5/9 x 27/1 C=5/1 x 3/1 C=5 x 3
A pound is a unit of? A) energy B) tenacity C) force D) density (wrong answer)
Force
A temperature reading of 85°C is equivalent to? A) 153° F B) 121° F C) 185° F D) 79.2° F
185°F F=(9/5 x C/1) +32 F=(9/5 x 85/1) +32 F=(9/1 x 17/1) +32 F=(9x17) +32
Density is a ratio between mass and? A) weight B) water C) volume D) velocity
Volume Density = Total Weight(Mass) / Volume.
When the temperature of a substance increases, or the pressure is reduced, the substance? A) expands and becomes more dense B) contracts and becomes less dense C) expands and becomes less dense D) contracts and becomes more dense
Expands & becomes less dense
If an object’s weight is 210lbs, and the volume is 3.5 cubic feet. What is the object’s density? A) 60 ft3 B) 60.5 ft3 C) 60 ft2 D) 16.6 ft3
60ft3 Density = Total weight/Volume D = 210lbs/3.5 ft3
Water has a density of 62.4lbs/ft3. The volume of 1,000 lbs of water is? A) 16 ft3 B) 43.3 ft3 C) 433 ft3 D) 62,000 ft3
16ft3 Volume = weight / density V = 1000 lbs / 62.4 lbs/ft3
What can be used to find the weight of objects which cannot be weighed on scales? A) buoyancy B) specific weight C) density D) specific gravity
specific gravity
A piece of concrete weighs 400 lbs in air and 350 lbs in water. What is its specific gravity? A) 80 B) 50 C) 8 D) 0.8
8 Specific Gravity = weight in air / weight in air - weight in water G=400lbs/400lbs-350lbs G=400/50
Specific weight most nearly means? A) Gravity B) volume C) force D) density
Density
Atmospheric pressure is? A) a vacuum B) pressure in a vessel C) a siphon D) greater at sea level
greater at sea level
The term “viscosity” most nearly means? A) Resistance to physical change B) ability to support an object C) the ability to exert force D) the tendency for molecules to stick together
Resistance to physical change
The pressure upward at any given point in a liquid is _______ the downward pressure at that point. A) less than (wrong) B) the same as C) greater than D) unrelated to
The same as (pg 27)
What is the pressure on the bottom of a discharge line at 200 ft deep? A) 12,580 lbs/ft2 B) 12,480 lbs/ft2 C) 240 lbs/ft2 D) 12,400 lbs/ft2
12,480 lbs/ft2 Pressure = height x density **denisty of water is 62.4 lbs P=200ft x 62.4lbs
A slanting penstock 2,000 ft long conveys water from a reservoir to a turbine 800 ft below the level of the reservoir. Pressure at the turbine is? A) 74,880 lbs/ft2 B) 49,920 lbs/ft2 C) 499.2 lbs/ft2 (wrong answer) D) 346.4 lbs/ft2
49,920 lbs/ft2 Pressure = height x density **denisty of water is 62.4 lbs P=800ft x 62.4lbs
