8.1 Physics of the Atmosphere

Question 1

What is the SI system?

Answer 1

Based on the metric system and must be used as law throughout the world

Question 2

What are the four fundamental units in aerodynamics?

Answer 2

Mass
Length
Time
Temperature

Question 3

What is the unit of measurement for mass and how is it denoted?

Answer 3

Kilograms (Kg)

Question 4

What is 1Kg measured against?

Answer 4

1 kilogram is also the volume of one litre of pure water at a temperature of 4° Celsius

Question 5

What is constant for astronauts in space; Weight or Mass?

Answer 5

Mass as weight is varied by gravity

Question 6

What is the unit of measurement for Length and how is it denoted?

Answer 6

Meteres (m)

Question 7

What year was the metre introduced and by whom?

Answer 7

French Government, 1790

Question 8

How is a metre defined?

Answer 8

A certain number of wavelengths of a particular colour of light.

Question 9

What is the unit of measurement for Time and how is it denoted?

Answer 9

Seconds (s)

Question 10

How is a second defined?

Answer 10

A fraction of the unchangeable speed of light.

Question 11

What is the unit of measurement for Temperature and how is it denoted?

Answer 11

Kelvin (K)

Question 12

What are the 6 basic quantities?

Answer 12

Speed
Acceleration
Power
Pressure 
Force 
Work

Question 13

What is the unit of measurement for Speed and how is it denoted?

Answer 13

Velocity (v)

Question 14

How do you calculate acceleration?

Answer 14

Time

Question 15

What is the unit of measurement for Acceleration and how is it denoted?

Answer 15

a (M/s*2)

Question 16

What is the unit of measurement for Acceleration due to Gravity and how is it denoted?

Answer 16

G (9.8m/s*2)

Question 17

What happens to persons weight if they are moving in an elevator with a constant velocity?

Answer 17

No change in weight

Question 18

What happens to persons weight if they are moving in an elevator which accelerates when moving up?

Answer 18

As the elevator accelerates, there is an additional force which increases the weight

Question 19

What is Newtons second law?

Answer 19

F=ma

Question 20

How do you calculate weight, and what is its’s units?

Answer 20

W=mg

Unit - Newtons

Question 21

How do you calculate work done, and what is its’s units?

Answer 21

Work = N x m

Work is denoted by Joule (J) and is measured in Newton metres

Question 22

How do you calculate Power, and what is its’s units?

Answer 22

Power = Force x Distance/ Time

Denoted by Watts

Question 23

How do you calculate Pressure, and what is its’s units?

Answer 23

Pressure = Force/ Area

Pascal (Pa)

Question 24

What is static pressure?

Answer 24

Static pressure acts equally in all directions. It is denoted by a small “p” and measured in Newtons per square metre.

Question 25

How do you calculate static pressure?

Answer 25

Height x density x gravity.

Question 26

What is dynamic pressure?

Answer 26

Dynamic pressure acts only in the direction of the flow. It is denoted by a small q and is sometimes called "q" pressure.

Question 27

How do you calculate dynamic pressure?

Answer 27

1/2 x density x v*2

Question 28

What is static pressure denoted by?

Answer 28

Bar and measured in deca-Newtons per square centimetre.

Question 29

What is 1 Bar equal to in Pascal?

Answer 29

100 000 Pascal.

Question 30

What are sound waves the same as?

Answer 30

Pressure Waves

Question 31

What is the speed of sound denoted by?

Answer 31

Small "a"

Question 32

What is the formula for the speed of sound?

Answer 32

20 x Square root of Temperature

Question 33

What is the constant in the speed of sound equation?

Answer 33

20

Question 34

Is the speed of sound is lower at high altitudes?

Answer 34

Lower because the temperature is lower.

Question 35

What is the pressure wave known as when an aircraft hits Mach 1?

Answer 35

Shockwave

Question 36

How is Mach calculated?

Answer 36

Speed of the aircraft/ Speed of sound.

Question 37

What are the three sound regions which are de ned by the Mach numbers?

Answer 37

Subsonic Transonic Supersonic

Question 38

What speed is included in the Transonic region?

Answer 38

Critical Mach Number to Mach 1.3

Question 39

What layer of the atmosphere has clouds and rain and many different weather conditions?

Answer 39

Troposphere

Question 40

What is unique about the stratosphere in regards to temperature?

Answer 40

Temperature does not change as the altitude increases.

Question 41

What height is the Tropopause over the poles?

Answer 41

8km

Question 42

What height is the Tropopause over the equator?

Answer 42

16km

Question 43

What does ISA stand for?

Answer 43

ICAO Standard Atmosphere

Question 44

Who created the standard atmosphere?

Answer 44

ICAO

Question 45

What is the standard altitude for the Tropopause?

Answer 45

11km

Question 46

How is the change of temperature calculated in the stratosphere?

Answer 46

There is no change in temperature in the stratosphere

Question 47

How are density and pressure impacted by altitude

Answer 47

The density and pressure gradually decrease with altitude

Question 48

What is the standard temperature of the tropopause?

Answer 48

-56.5 Celsius

Question 49

Under standard conditions what does the temperature vary with at increasing altitude?

Answer 49

6.5 celsius per km