Subject J – Basic Physics

Question 1

What is matter?

Answer 1

Anything that occupies space and has mass.

Question 2

What are the different states of matter?

Answer 2

Solid, liquid, gas, plasma.

Question 2

What are two types of fluids

Answer 2

Liquids and gasses.

Question 3

When a fluid passes through the middle section of a venturi, what pressure and velocity changes occur?

Answer 3

Pressure decreases and velocity increases.

Question 4

Are liquids compressible?

Answer 4

No. liquids are incompressible.

Question 5

What is the standard atmospheric pressure at sea level?

Answer 5

It is considered to be 14.7 psi or 29.92 inches of Hg (mercury).

Question 6

What is the standard day temperature?

Answer 6

59 Fahrenheit.

Question 7

What is the name of the atmospheric phenomenon where cool air is trapped near the earth by warm air?

Answer 7

A temperature inversion.

Question 8

What is the speed of sound through the air under standard sea level conditions?

Answer 8

761 mph.

Question 9

What is meant by the density of air

Answer 9

The mass of a given volume of air.

Question 10

What determines the density of the air? (In other words density altitude.)

Answer 10

Density altitude is a calculated altitude obtained by correcting pressure altitude for temperature.

Question 11

What does specific gravity mean?

Answer 11

It is the ratio of a substance’s density to the density of pure water.

Question 12

What are the three basic parts of a lever?

Answer 12

The fulcrum, force of effort, and resistance.

Question 13

What is a first class lever, and give an example?

Answer 13

A first class lever is when the fulcrum is located between the effort and the resistance. An example of a first class lever is a seesaw.

Question 14

In what direction is force transmitted to a confined liquid?

Answer 14

Force is transmitted equally in all directions because it cannot be compressed.

Question 15

What is the formula for computing force, pressure, and area (Pascal’s Law)?

Answer 15

Force equals pressure times area or F = P x A.

Question 16

What is kinetic energy?

Answer 16

Energy in an object created from its movement (energy in motion).

Question 17

What is potential energy?

Answer 17

stored energy.

Question 18

What is absolute zero?

Answer 18

It is the temperature at which all motion of the atoms will cease entirely in a given sample of gas (the temperature at which the atoms will be motionless). It is considered to be -459.

Question 19

What are the two factors involved in work?

Answer 19

Force and movement through a distance.

Question 20

How is pressure expressed in hydraulics and pneumatics?

Answer 20

It is expressed in pounds per square inch (psi).

Question 21

Name the forms of energy that can be converted into heat energy?

Answer 21

Mechanical, electrical, chemical, radiant, nuclear, and solar.

Question 22

What are the three methods of heat transfer?

Answer 22

Conduction, convection, and radiation.

Question 23

What are the three types of friction?

Answer 23

Rolling, Sliding, and Static

Question 24

What are the four forces experienced by an aircraft in flight?

Answer 24

weight, thrust, lift, and drag.

Question 25

What is an autorotation?

Answer 25

An autorotation is when the helicopter rotor blades spin without engine power as air flows through the rotor.

Question 26

What is the name of the imaginary line that runs from the leading edge to the trailing edge of an airfoil?

Answer 26

Chord line.

Question 26

How does blade flapping help compensate for dissymmetry of lift in helicopter main rotor systems?

Answer 26

By increasing the angle of attack on the retreating blade, and decreasing angle of attack on the advancing blade.

Question 27

What function do wing mounted vortex generators serve?

Answer 27

Vortex generators prevent airflow separation from the upper surface of the wing

Question 28

What is directional stability?

Answer 28

The ability of an aircraft to avoid yawing.

Question 29

What is the name of a tube that converges to a smaller diameter and then diverges back to its original diameter and can be used to demonstrate Bernoulli's Principle?

Answer 29

A venturi

Question 30

What is the term used to describe the ratio of speed of an aircraft to the speed of sound?

Answer 30

Mach number.

Question 31

What is the characteristic of wing design called that adds an upward lateral angle of a few degrees from horizontal?

Answer 31

Dihedral.

Question 32

What term is used to describe the rate of speed and direction?

Answer 32

Velocity

Question 33

What is the definition of sliding friction?

Answer 33

Sliding friction is the resistance to motion offered by an object sliding over a surface.

Question 34

What class lever is a seesaw?

Answer 34

1st Class lever

Question 35

Describe longitudinal stability.

Answer 35

The aircrafts ability to not be adversely affected by a force around its lateral axis creating a pitching type motion.

Question 36

Describe lateral stability.

Answer 36

The aircrafts ability to not be adversely affected by a force around its longitudinal axis creating a rolling type motion.

Question 37

What is the angle between the chord line of an airfoil and the direction of the relative wind called?

Answer 37

Angle of attack.

Question 38

Name at least 2 types of stresses that may act on an aircraft.

Answer 38

Strain, Torsion, Bending, Shear, Tension, Compression

Question 39

What causes an airplane wing to stall?

Answer 39

If the angle of attack becomes too great, the airflow can separate from the wing and the lift will be destroyed.

Question 40

What is the name of the angle between the chord line of a wing and the longitudinal axis?

Answer 40

Angle of incidence.

Question 41

how does blade flapping help compensate for dissymmetry of lift in helicopter main rotor systems?

Answer 41

Blade flapping serves to increase the angle of attack (and lift) on the retreating blade side of the rotor and decrease the angle of attack (and lift) on the advancing blade side.

Question 42

What have physicists used in comparing the densities of all solids and liquids?

Answer 42

Water

Question 43

What type of wind is parallel and opposite to the direction of flight?

Answer 43

Rotation relative wind

Question 44

What class of lever is a wheelbarrow?

Answer 44

A second-class lever.

Question 45

How is pressure expressed in hydraulics and pneumatics?

Answer 45

Pounds per square inch.

Question 46

Name 3 temperature scales.

Answer 46

Name 3 temperature scales.