Heat and Liquids

Question 1

Heat

Answer 1

A form of energy that expresses itself in the movement of molecules

Question 2

Temperature

Answer 2

The average speed of molecules in a body

Question 3

Temperature Scales

Answer 3

Fahrenheit
Celsius
Kelvin (Fahrenheit absolute scale)
Rankin (Celsius absolute scale)

Question 4

Absolute Zero

Answer 4

The point where all molecular motion stops

0 degrees on both the Kelvin and Rankin scales

Question 5

Temperature Conversions

Answer 5

(9/5 C) + 32 = F
5/9 (F - 32) = C
F + 460 = R
R - 460 = F
C + 273 = K
K - 273 = C

Question 6

Heat Energy Measurement

Answer 6

Heat Energy is measured in British Thermal Unit (BTU) or Calories

Question 7

1 BTU

Answer 7

Raise 1 pound of water 1 F

Question 8

1 Calorie

Answer 8

Raise 1 gram of water 1 C

Question 9

1 BTU Equals

Answer 9

778 ft. lbs of work

Question 10

Specific Heat

Answer 10

Number of BTUs needed to raise 1 pound of a substance 1 F

Question 11

Sensible Heat

Answer 11

Number of BTUs needed to raise the temperature of an object 1 F

Question 12

Latent Heat

Answer 12

Number of BTUs required to cause a substance to change its state without causing a change in its temperature

Question 13

Conduction

Answer 13

Heat transfer between objects in physical contact

Question 14

Convection

Answer 14

Heat transfer by means of working fluids (gases or liquids)

Question 15

Radiation

Answer 15

Heat transfer by means of electromagnetic waves

Works in a vacuum and occurs at the speed of light

Question 16

Gases Behavior

Answer 16

Takes shape of its container

Expands uniformly to completely fill its container

Is easily compressible

Question 17

Pressure Measurement Units

Answer 17

Pounds per square inch absolute - PSIA

Pounds per square inch gauge - PSIG

Question 18

Relationship Between Absolute and Gauge

Answer 18

PSIG + 14.7 = PSIA
PSIA - 14.7 = PSIG

Question 19

Boyle’s Law

Answer 19

Volume is inversely proportional to absolute pressure when temperature is held constant

P1 x V1 = P2 x V2

Question 20

Charles’ Law

Answer 20

Volume is directly proportional to absolute temperature when pressure is held constant

V1 / T1 = V2 / T2

Question 21

Guy-Lussac’s Law

Answer 21

The pressure of a confined gas is directly proportional to the absolute temperature when the volume is held constant

P1 / T1 = P2 / T2

Question 22

General Gas Law

Answer 22

A combination of the three gas laws can be used to replace any gas law equation, and take out constants if any. (WARNING: Both temperature and pressure must be in an absolute values before performing gas law calculations

(Pressure 1 x Volume 1) / Temperature 1 =
(Pressure 2 x Volume 2) / Temperature 2

Question 23

Liquids Behavior

Answer 23

Takes the shape of its container, has a defined volume, is incompressible

Question 24

The pressure of the fluid in a container depends on…

Answer 24

The height of the column (hydraulic head), and the density of the fluid

Question 25

Buoyancy

Answer 25

The upward force exerted by a liquid on a body immersed or submerged in it

Question 26

Archimedes Principle

Answer 26

The buoyant force which a fluid exerts upon a submerged body is equal to the weight of the fluid the body displaces

Question 27

Displacement of a Floating Object

Answer 27

It will displace its own weight in fluid

Question 28

Hydraulics

Answer 28

The branch of science that deals with the transmission of forces by incompressible fluids under pressure

Question 29

Hydraulic Formulas

Answer 29

Force = Area x Pressure A = Area of a working piston (input or output) P = System Pressure F = input (applied) or output (created)

Question 30

Hydraulics Theory

Answer 30

Force applied to an input piston produces a system pressure which is inversely proportional to the input piston area System pressure applied to an output piston produces a force directly proportional to the piston area and system pressure

Question 31

Mechanical Advantage

Answer 31

MA = A (out) / A (in) = F (out) / F (in) Distance advantage is inverse of mechanical advantage

Question 32

Displacement of a Submerged Object

Answer 32

It will displace its own volume in fluid

Question 33

Buoyancy Equation

Answer 33

Buoyancy Force = Volume of the Object x Density of the Fluid Displaced