Physics Terms Flashcards
Matter
Any substance that has mass and takes up space
Mass
A measure of quantity of matter in an object
Molecule
A group of atoms bonded together
Weight
A measure of the pull of gravity acting on the mass of an object
Impenetrability
No two objects that can occupy the same place at the same time
Density
The weight of a substance per unit volume OR A measure of how compact the mass is in a substance or object
Specific Gravity
The ratio of the mass of a solid or liquid to the mass of an equal volume of water
SG of water is 1.000
SG of Air is 1.000
Hydrometer
An instrument used to determine/measure the Specific Gravity of liquids
Energy
Something that gives us the capacity
Potential Energy
Energy that is stored/at rest
Example: Your phone on the table
Kinetic Energy
Energy due to motion
Example: An airplane rolling down the runway
Force
The intensity of an impetus, or the intensity of an input (The amount of pressure given to an area)
Work
The amount of energy transferred by force (A force acting through a distance)
Friction
The action of one surface or object rubbing against another
Static Friction (Starting Friction)
A force that keeps an object at rest
Example: A book sitting on a table
Sliding Friction
The resistance created by any 2 objects when sliding against each other
Example: Sledding or a car sliding on ice
Rolling Friction
The frictional force that occurs when one object rolls on another
BTU (British Thermal Unit)
A unit measurement for heat and is defined as the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit
BTU is capable of 778 ft-lb of work
Power
The rate at which an aircraft transfers energy or does work
(How long it takes to accomplish the work)
Horsepower
A measure of power equal to 550 foot-pounds per second or 33,000 foot-pounds per minute and 746 watts
Torque
The force that causes an object to rotate around an axis
(This causes twisting)
Simple Machines
The most basic machines with few parts that can modify motion and force to perform work
Screws hold assemblies together.
Pulleys that transmit power to.
Levers that actuate different assemblies and components.
Mechanical Advantage
A ratio of the output force to the input force of a simple machine (A comparison)
The Lever
The simplest machine that uses a beam.
There are 3 basic parts in all levers, Fulcrum, Effort, Resistance (Load)
The Pulley
Simple mechanical devices that use one or more wheels and a cable to apply pulling force in airplanes
Single Fixed Pulley
A type of pulley that’s attached to a fixed axis and can’t move. It can’t reduce effort, it only changes the direction of motion.
(This is viewed as a 1st class lever)
(It’s MA =1 because it’s supported by 1 rope)
Single Movable Pulley
A pulley that’s free to move up and down, and is attached to a ceiling or other object.
(This pulley will act as a 2nd class lever)
(It’s MA = 2 because it’s supported by 2 ropes)
Block and Tackle
A system consisting of 2 or more pulleys with a rope, cable, or chain between them.
(Some are fixed and some are movable)
The Gear
The gears with teeth
(They act like a 1st class lever when one gear drives the other)
(The. gear with the input force is called the “Drive Gear” and the other is called “The Driven Gear”)
Inclined Plane
A simple machine that allows the raising or lowering of heavy objects by using the normal force of the plane
Stress
The internal resistance of an object to external forces attempting to strain or deform that object
(Stress is measured in psi)
Tension
The force that tries to pull an object apart by pulling in opposite directions along the same straight line
Compression
A force that tries to crush an object, this applies to pressure and exertion against an object to become squeezed or compacted
Torsion
The loading case that creates a twisting movement
(Which is what happens when torsion is applied to a shaft)
Bending
A combination of tension and compression
Example: When the force of lift causes the skin on the top of the wing to compress and the skin on the bottom of the wing to be under tension
Shear
When shear stress is applied to an object the force trues to cut or slice through
Example: A knife cutting through butter
Strain
A change in shape on an object due to stress (applied force)
Motion
The study of bodies or objects and the force acting on them
(Force and Motion)
Uniform Motion
When the distance the object moves remains the same for a given period of time, which means it always stay at constant speed
Speed and Velocity
Speed refers to how fast an object is moving or how far
Velocity refers to speed and direction of an object
Acceleration
The rate of change of velocity
(Measured in 32.2 fps/s)
Absolute Zero
The lowest temp possible. At the temp of absolute 0 there is no motion and no heat, it’s the coldest temp
Circular Motion
The motion of an object along a curved path that has a constant radius
Example: The moon orbiting around the earth
Centripetal Force
A force acting toward the center of the curve defined by the curving flight path
Centrifugal Force
A force acting away from the center of the curve traced out by the curving flight path
Heat
Energy that’s transferred from one body to another as a result of a difference in temp
Thermal Efficiency
The ability to convert the chemical energy of the fuel into mechanical work
Convection
The transfer of heat between 2 bodies by currents of moving gas or fluid
Example:
Conduction
When heat moves from one object to another through direct heat touch
Example: Boiling water on a stove
Radiation
A process where heat waves are emitted that may be absorbed, reflected, or transmitted through a colder body
Example: A bonfire
Specific Heat
A heat required to raise the temp of the unit mass of a given substance by a given amount
Temperature
The measure of heat or cold expressed in terms of C or F
Pressure
The amount of force acting on a specific amount of surface area
Gauge pressure
Pressure variations from ambient pressure
Means the system will read the pressure to its maximum but once it turns off its pressure drops to 0.
Starts at 0 as well.
Kinetic Theory of Gases
Describes a gas as a large number of particles like atoms or molecules, all of which are in constant, random motion
Absolute Pressure
Pressure that includes atmospheric pressure, which is 14.7 psi or whatever it may be where you are but never is 0.
Used to determine altitude by measuring air pressure in the atmosphere.
Differential Pressure (psid)
The difference in pressure between 2 different locations within a system
Boyles Law
The volume of a container decreases, the pressure of the gas inside will increase
Charles Law
Explains how gases expand as they are heated
Daltons law
The total pressure of a gas mixture is equal to the sum of the pressure that each gas would give out independently
Buoyancy
An object that’s less dense than water floats because the water is heavier than the object
Fluid Pressure
A measurement of the force per unit area that acts on an object in the fluid or on a closed containers surface by height not shape
Pascals Law
That pressure set up in a fluid acts equally in all directions
Bernoullis Principle
Explains the action of a liquid flowing through the varying cross sectional areas of tubes
Example: A tube is shown in which the cross-sectional area gradually decreases to a minimum diameter in its center section. A tube constructed in this manner is called a “venturi,” or “venturi tube.” Where the cross-sectional area is decreasing, the passageway is referred to as a converging duct.
Example 2: The flow of air over an airplane wing or the flow of water through a pipe
Sound
A series of disturbances in matter that the human ear can detect
Wave Motion
The transfer of energy and momentum from one point of the medium to another point of the medium without the actual transport of matter between two points
Example: Ripples in water
Speed of Sound
How fast vibrations travel
Mach Number
The ratio of flow velocity after a certain limit of the sounds speed
Frequency of Sound
The number of times per second that a sound pressure wave repeats itself
Doppler Effect
The increase or decrease in the frequency of sound, light or waves as the source moves toward or away from each other
(it explains why the sound from an airplane seems different as it approaches compared to how it sounds as it flies overhead)
The Atmosphere
Data available about the atmosphere may determine whether a flight will succeed, or whether it will even become airborne