General - Physics

Matter?

what all things are made of

Mass?

a measure of the quantity of matter in an object

Molecule?

the smallest particle of an element or compound that retains the chemical properties of that element or compound

What is the name for the basic building block of all matter?

Atom

List the three physical states of matter?

Solid, Liquid, Gas

Weight?

a measure of the force of gravity acting on the mass of an object

Density?

the weight of a substance per unit volume

What is the specific gravity of water?

1

A device that measures the specific gravity of a liquid is called a?

Hydrometer

What is Work in the mechanical sense?

is the force acting on an object that causes the object to move in the direction of the force

What is Potential energy and give an example?

stored energy or energy at rest like a Boeing 747 positioned at a height of 4 feet off the ground

What is Kinetic energy and give an example?

energy that is in motion like an Airbus A380 moving down a runway during its takeoff roll

One Horsepower is equal to how many watts of electrical energy?

746 watts

Name the five types of stress found in mechanical bodies?

tension, compression, torsion, bending and shear

Formula for Mass?

weight/gravity

Formula for Weight?

mass x gravity

Formula for Potential Energy?

weight x height

Formula for Kinetic energy?

1/2mv²

Specific Gravity?

density of the substance/density of water

Formula for Force?

mass x acceleration

Formula for Work?

force x distance

Formula for Power?

force x distance/time

Torque?

force x distance

Mechanical Advantage?

force out/force in or distance out/distance in

First class lever? (ex: seesaw or the CG of aircraft)

can be made to gain force or distance but not at the same time.

Second class lever? (ex: wheelbarrow)

can only be made to gain force

Third class lever? (ex: The retractable main landing gear)

is desirable to speed up the movement of the resistance even though a large amount of effort must be used

When calculating how much effort is required to lift a specific weight, or how much weight can be lifted by a specific effort, the following formula can be used?

effort x effort arm = resistance x resistance arm

Tension?

a force that tries to pull an object apart

Compression?

a force that tries to crush an object

Torsion?

the stress an object experiences when it is twisted

Bending?

An airplane in flight experiences a bending force on the wing as aerodynamic lift tries to raise the wing

When a Shear stress is applied to an object?

the force tries to cut or slice through

If the Strain acting on an object is great enough it can cause the object to?

change its shape or become distorted

Speed?

Speed refers to how fast an object is moving, or how far the object will travel in a specific time

Velocity?

denotes both the speed and the direction in which the object moves

Acceleration?

rate of change of velocity

Formula for Acceleration?

velocity final-velocity initial/time

Newton’s first law of motion?

objects at rest tend to remain at rest and objects in motion tend to remain in motion at the same speed and direction unless acted on by an external force

Newton’s second law of motion?

when a force acts upon a body, the momentum of that body is changed

Newton’s third law of motion?

for every action there is an equal and opposite reaction

When talking about Heat Energy Units, one calorie is equal to the amount of?

heat required to change the temperature of 1 gram of water 1 degree centigrade

One BTU?

the amount of heat required to change the temperature of 1 lb of water 1 degree Fahrenheit

Formula for Thermal Efficiency?

horsepower produced/potential horsepower in fuel

What are the three methods of heat transfer, that transfer from one location to another or from one substance to another?

conduction, convection and radiation

Each substance requires a quantity of heat, called its specific heat capacity, to increase the temperature of a unit of its mass 1 °C. The specific heat of a substance is?

the ratio of its specific heat capacity to the specific heat capacity of water

what is Pressure?

the amount of force acting on a specific amount of surface area

Standard day atmospheric pressure is equal to?

14.7 psi or 29.92 inches of mercury (HG)

Absolute Pressure (psia)?

a gauge that includes atmospheric pressure

Gauge Pressure (psig)?

instrument displays pressure that is above ambient

Differential Pressure (psid)?

the difference between pressures being read at two different locations within a system

Boyle’s Law?

The volume of an enclosed dry gas varies inversely with its absolute pressure, provided the temperature remains constant

Formula for Boyle’s Law?

v1p1=v2p2

Formula for Charles’ Law?

v1t2 = v2t1

By combining Boyle’s and Charles’ laws, a single expression can be derived which states all the information contained in both. The formula which is used to express the general gas law is as follows

p1v1/t1=p2v2/t2

Buoyancy?

A solid body submerged in a liquid or a gas weighs less than when weighed in free space

Buoyant force?

Volume of Object × Density of Fluid Displaced

Fluid pressure?

The pressure exerted on the bottom of a container by a liquid is determined by the height of the liquid and not by the shape of the container

Formula for Force?

Pressure x Area

Formula for Pressure?

Force/Area

Mach number?

ratio of the speed of an aircraft to the speed of sound in the surrounding medium

Velocity of sound?

760 mph at 59 F

Sound Intensity?

measured in decibels, with a decibel being the ratio of one sound to another

Absolute Humidity?

the actual amount of water vapor in a mixture of air and water

Relative Humidity?

the ratio of the amount of water vapor actually present in the atmosphere to the amount that would be present if the air were saturated at the prevailing temperature and pressure

Dew Point?

temperature to which humid air must be cooled at constant pressure to become saturated

Atmospheric Density?

decreases as altitude increases because there's less air above pushing down, resulting in lower pressure

Vapor Pressure?

pressure exerted by water vapor present in the air

Chord line?

an imaginary straight line running from the wing’s leading edge to its trailing edge

The angle between the chord line and the longitudinal axis of the airplane is known as the?

angle of incidence

Angle of Attack?

angle between the chord line and the relative wind

Relative Wind?

relationship between the direction of airflow and the wing, it is opposite to the direction of the aircraft

Wingtip Vortices?

caused by the air beneath the wing, which is at the higher pressure flowing over the wingtip and up toward the top of the wing

Three axes of rotation of an aircraft?

longitudinal, lateral and vertical

Longitudinal stability for an airplane involves?

the tendency for the nose to pitch up or down around its lateral axis when its equilibrium in flight is disrupted

Lateral stability (Longitudinal axis)?

If one wing is lower than the other, good lateral stability will tend to bring the wings back to a level flight attitude

Wing Dihedral?

upward angle of the wings that increase stability

Lateral Axis?

a line that runs from wingtip to wingtip passing through the center of gravity

Trim Tabs?

small movable surfaces that attach to the trailing edge of flight controls

Three main flight controls of a helicopter?

cyclic, collective and anti torque pedals

what does a helicopter’s tail rotor do?

provides a counteracting force to the helicopter's main rotor

Helicopter’s Collective governs the?

amount of lift produced by the main rotor blades

The Cyclic controls the helicopter's?

direction by tilting the plane of the main rotor disc

Anti-Torque pedals control the helicopter’s?

heading by adjusting the amount of thrust produced by the tail rotor

Charles’ Law?

volume and temperature are directly proportional at constant pressure

The speed of sound in the atmosphere?

changes with a change in temperature

A fully charged lead acid (aircraft battery) will have a specific gravity reading between?

1.270 and 1.310

Heating an object will cause it to?

expand

If the fluid pressure is 800 psi in a ½ inch line supplying an actuating cylinder with a piston area of 10 square inches, the force exerted on the piston will be?

8000 lbs

Weight=400 lbs, Effort=100 lbs MA=

4

Effort=500 lbs, Weight=250 lbs MA=

.5

Mechanical advantage of 10, Weight = 1000 pounds  Effort =

100

Mechanical advantage of 2, Effort of 50 pounds Weight =

100

Determine the amount of force required at “B” to balance this lever

A = 20 pounds, Moment A= Moment B=

B=

300 and 10

Which wing would produce more lift?

flaps down

L/I=R/E =

length/height ramp=weight of object/force

With Liquids?

atoms are spread out

With Gases?

atoms are spread far apart and are compressible

Solids have?

very little heat energy with atoms close together

When a first class lever has equal arms, the mechanical advantage is 1, thus, the force of the pull on the rope must be?

equal to the weight of the object being lifted