 # Basic Hydraulics Density, Specific Gravity

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Basic Hydraulics Density, Specific Gravity
Math for Water Technology MTH 082 and Water Works Operation WQT 111 Lecture 4 Hydraulics Chapter 1 (pgs )

Objectives/Discuss Density Specific Gravity Bulk Density
Density of a Fluid

What is Density? Density= Mass/Volume ρ = m / V
The weight per unit of volume. Density= Mass/Volume ρ = m / V ρ is the object's density (measured in kilograms per cubic meter) m is the object's total mass (measured in kilograms) V is the object's total volume (measured in cubic meter) Units: lb/ft3 (sand, activated carbon, lime, soda ash, air, chlorine gas, methane, carbon dioxide) lb/gal (water, liquid aluminum, liquid chlorine)

A substance weighs 378 g and occupies a space of 48 cm3
A substance weighs 378 g and occupies a space of 48 cm3. What is its density in grams per cubic centimeter? g/cm3 7.9 g/cm3 18,144 g/cm3 378 g/cm3

What is the density in pounds per gallon of a 1
What is the density in pounds per gallon of a 1.00 L solution that weighs 2.29 lb? 2.29 lb/gal 8.67 lb/gal 0.12 lb/gal 0.43 lb/gal

The density of an unknown substance is 2. 14 g/cm3
The density of an unknown substance is 2.14 g/cm3. How much space would this substance occupy in cubic centimeters if it weighed 3.3 lb? We know that 2.14 g of substance occupies 1 cm3 by knowing its density. To get the space 1,498.2 g occupies, divide by the density. 700 cm3 0.015 cm3 0.65 cm3 1500 cm3

The density of a substance changes slightly as the temperature of the substance changes.
(T) Substances increase in size (expand volume) as they become warmer. Density is lower in warm substance but greater in cold substances, cool=condense True False

What is Density? 2 ft3 or 0.1 lb 1 ft3 or 0.1 lb Cold Higher Density
Warm Lower Density

In water supply operations, the density of water varies slightly with temperature.
(T) However, at the constant temperatures in water supply operations the change is negligible. True False

Water is the most dense at 39
Water is the most dense at 39.2 oF and becomes less dense when the temperature rises or falls. (T) water is an unusual substance that acts differently from everything else.. True False

What is Bulk Density? Bulk density is the weight of a cubic foot of material as it would be shipped from the supplier to the treatment plant. It is the mass of many particles of the material divided by the volume they occupy. The volume includes the space between particles as well as the space inside the pores of individual particles. Bulk density is a measure of the weight of the substance per unit volume (g/cc). Includes volume of the air, amount of air

This physical property is what prevents salt and freshwater from mixing in an aquifer or underground basin. Specific gravity is related to density. Since the seawater is more dense, it doesn't mix freely with the freshwater. It's similar to what happens with water and oil. Specific gravity Temperature pH Van der waals forces

What is specific gravity of a liquid?
Specific Gravity- is the density of a substance relative to the standard density of water which is 62.4 lb/ft3 or 8.34 lb/gal. It’s a ratio of a substances density to that of water. SG= density of substance 62.4 lb/ft3 or 8.34 lb/gal SG is used as a way to compare to separate materials. Its done at a fixed temperature and pressure for a given substance.

Example 1. The density of granite rock is 162 lb/ft3 and the density of water is 62.4 lb/ft3. What is the specific gravity of granite? 162 lb/ft3 62.4 lb/ft3 162 lb/ft3 = 62.4 lb/ft3

Example 2. The density of SAE motor oil is 56 lb/ft3 and the density of water is 62.4 lb/ft3. What is the specific gravity of the motor oil? 56 lb/ft3 62.4 lb/ft3 56 lb/ft3 = ; its 9/10 as dense as water! 62.4 lb/ft THAT’S WHY OIL FLOATS ON H2O

Example 3. The density of aluminum is 168 lb/ft3 and the density of water is 62.4 lb/ft3. What is the specific gravity of the aluminum? 168 lb/ft3 62.4 lb/ft3 168 lb/ft3 = 62.4 lb/ft3

Example 4. The specific gravity of SAE motor oil is 0
Example 4. The specific gravity of SAE motor oil is 0.92 and the density of water is 62.4 lb/ft3. What is the density of the motor oil? 0.92= ??? lb/ft3 62.4 lb/ft3 (X) lb/ft3 = ; (X lb/ft3) = 62.4 lb/ft3 (0.92) 62.4 lb/ft3 (X) = lb/ft3

Pumped Conversion Rate
Example 5. Suppose you wish to pump a certain liquid at the rate of 25 gpm. How many lb per day will be pumping if the liquid weighs 74.9 lb/ft3? 74.9 lb/ft3 74.9 lb/ft3 = 62.4 lb/ft3 H20 Specific Gravity 8.34 lb/gal (1.20) =10.01 lb/gal Pumped Conversion Rate (25 gpm) (10.01 lb/gal) (1,440 min/day) = 360,360 lb/d pumped

A fluid with a specific gravity of 1.05 weighs _____ lb/gal.
Given : Sg= Need lb/gal Conversions 8.34 lb/1gal 8.34 lb (1.05) = 8.75 lb/gal gal 8.4 8.8 7.2 8.5

If water weighs 8.34 lbs/gal, how much will 7.5 gal weigh?
Given : 8.43 lbs/gal and 7.5 gal Conversions 8.34 lb/1gal 8.34 lb (7.5 gallons) = 63 lbs gal 50.8 lbs 62.6 lbs 75.5 lbs 77.3 lbs

1240 gal 0.93 SG H20 Specific Gravity 8.34 lb/gal (0.93) =7.76 lb/gal
Example 6. There are 1,240 gal of a certain liquid in a tank. If the specific gravity of the liquid is 0.93, how many pounds of liquid are in the tank? 1240 gal 0.93 SG SG=0.93 H20 Specific Gravity 8.34 lb/gal (0.93) =7.76 lb/gal Conversion Rate (7.761 lb/gal) (1240 gal) = 9,622 lb

A liquid has a specific gravity of 1
A liquid has a specific gravity of How much would 300 gallons of this liquid weigh? Given : Sg= 1.16 and 300 gallons?? Need weight Conversions 8.34 lb/1gal 8.34 lb (300 gallons) = 2502 lbs gal 2502 lbs (1.16) = 2902 lbs 2902 pounds 348 pounds 2502 pounds 2156 pounds

What is specific gravity of a gas?
Specific Gravity- is the density of a gas substance relative to the standard density of air which is lb/ft3 at 20oC and a pressure of 14.7 psia (pounds per square inch absolute)

Cl2 Specific Gravity = 0.187 lb/ft3 / 0.075 lb/ft3 = 2.49
Example 7. The density of chlorine gas is lb/ft3. What is the specific gravity of this gas? Specific gravity of Cl2 gas= (density of Cl2 gas) density of air Cl2 Specific Gravity = lb/ft3 / lb/ft3 = 2.49 Chlorine gas is about 2.5 times as dense as air

Today’s objective: to discuss the concept of density and specific gravity has been met.
Strongly Agree Agree Neutral Disagree Strongly Disagree