08-29-07
PHYSICS !!! - THE SCIENCE DEALING WITH NATURAL LAWS AND PROCESSES AND THE STATE AND PROPERTIES OF MATTER AND ENERGY.
08-31-06
Parameter: Any of a set of physical properties whose values determine the characteristics or behavior of something, e.g. parameters of the atmosphere such as temperature, pressure and density.
Distance: The amount of separation between two points, lines, surfaces or objects that's directly dependent on the path traveled between those two points, lines, surfaces or objects.
09-05-06
Displacement: The straight-line distance between the initial and final locations of an object, and its direction from the initial location to the final location. Not to be confused with a volume of water equivalent moved by a water vessel.
09-06-06
· Vector - Any parameter/quantity that requires both magnitude and direction for a complete description. Represented as arrows (of proportional length and specific direction) on F.B.D's (Free Body Diagrams).
· Scalar - Any parameter/quantity that can be fully described by magnitude alone (direction would not apply).
09-07-06
Magnitude - The size, extent, amount of, or dimension of any physical parameter/characteristic, inclusive of applicable units.
09-08-06
Per - For each or for every, e.g. that car is traveling at a speed of 55 miles per hour.
Conversion Factor - A numerical factor used to multiply or divide a quantity when converting from one unit or set of units to another.
09-11-06
Greek letter “D” = representative of a change in some physical parameter or Final Condition minus Initial Condition.
Average velocity (VAVG) = [Total Distance] / [Total Time] = D d / D t = [df - di]/ D t = Final Displacement - Initial Displacement divided by the total time elapsed during the event of concern.
09-12-06 Greek Letter Sigma => "S", as representative of the summation of the total of a number of like individual parameters as in:
Vavg = [Total Distance] / [Total Time] = S d’s / S t’s.
09-15-06
Acceleration (a) = [DV / Dt] = [Vf - Vi]/ D t = Final Velocity minus Initial Velocity divided by the total time elapsed during the event of concern.
09-21-06
Deceleration - A special case of acceleration when the Final Velocity (Vf) is lower in absolute value than the Initial Velocity (Vi) after any given time period (Dt) of interest. NOTE: Our text definition notwithstanding, not necessarily always a characteristic of a negative acceleration, e.g. the acceleration of gravity is considered in this class (by x-y coordinate convention) to be negative (i.e. - 9.81 m/s2)) yet certainly objects pick up speed (increase in absolute value) when falling under its influence.
Trajectory - The parabolic curved path that any projectile follows (in the absence of air resistance) while under the influence of gravity but having left contact with its original motive force.
09-25-06
Note Taking - The Art of Note Taking
Free-Fall - A type of problem or condition of an object, wherein the object is acted upon by the unrestrained force of gravity in the atmosphere or immediate vicinity of the Earth or other planetary body - though at times "wind-resistance" is taken in to account as applicable.
Terminal Velocity - The final (or maximum) velocity an object reaches during "Free-Fall" when air resistance is not ignored - i.e. the velocity of an object in "Free-Fall" that has stopped accelerating due to a balancing of the downward force due to gravity with the upward force due to wind resistance.
Instantaneous Velocity - The velocity of an object at any given instant in time which may or not be equal to the average or other characteristic velocity of that object at that time.
10-27-06
Mass - The amount of "stuff" or matter an object has in it. Also a measure of the inertia (or degree of difficulty an object is to movement).
Net (as in "Net" Force) - The overall resulting magnitude (& direction) of the single Force that would have otherwise produced the same affect as any number of different Forces acting on an object (e.g. if one person pushes on an object with a force of 100 Newtons to the right and another person pushes on that same object with a Force of 50 Newtons to the left - the "Net" resulting force would be 50 Newtons to the right).
Resultant (as in "Resultant" Force) - Same as "Net" above.
Force - A "Push" or a "Pull". A "Push" is considered a Compressive Force. A "Pull" is considered a Tension or Tensile Force. Forces can be additionally characterized as being "contact" (i.e. exerted via direct physical contact between two objects) or "non-contact" (e.g. gravitational or electro-magnetic). Measured in "Newtons" in the Metric (SI) System. A Force, if of sufficient magnitude and/or direction, can change the state of motion of an object.
Equilibrium - The Newtonian condition of an object when the sum of the Forces (i.e. the "Net" or "Resultant" Force) acting on that object is zero - which occurs when the object is at rest or traveling at constant velocity (i.e. when the object's acceleration is zero).
F.B.D. => FREE BODY DIAGRAM - The representation of an object, free from its surroundings, with all Forces on the object represented as vector arrows.
Statics - The engineering discipline involving the study of forces involved with objects in equilibrium.
12-11-06
Perpendicular - The condition when the long-axis centerlines of two objects/things meet one another at right angles.
Parallel - The condition when the long-axis centerlines of two objects/things are continually equidistant from one another.
Work - The quantity of Physics, relative to any given object, that is equivalent to the product of the Force applied to the object times the Distance the object is moved by that force. In this context the involved Force and Distance must be parallel to one another. A Force of One Newton that is used to move an object One Meter represents Work done of One (Newton)(Meter) or One (Joule).
Energy - The ability to do Work. Units of Energy are Joules.
Power - The rate of doing Work or consuming Energy. The basic unit of Power is the Watt, which is equivalent to One Joule per Second.
Kinetic - Having to do with movement or speed, as in Kinetic Energy which, for any given object is the product of one-half times the object's mass times the square of the object's speed, in Joules.
Potential (as in Potential Energy) - For any object, having to do with the Energy available from the object, as a function of the relative height of the object and is equivalent to the product of the mass of the object (in Kilograms), the acceleration of gravity at the point of the object (in Meters/Sec2) and the relative height of the object (in Meters).
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05-07-07
AMPLITUDE - In any (transverse) wave or vibration, the particles which are taking part in the wave motion or vibration will move away from the positions they had before the wave existed, or the vibration took place. The maximum distance the particles move from these undisturbed or equilibrium positions is the amplitude of the wave or vibration. For transverse mechanical waves, amplitude may be measured in meters. For sound waves, amplitude is measured in decibels, which are abbreviated dB.
WAVELENGTH - Distance between corresponding points on two successive waves.
FREQUENCY - How often an event occurs; the frequency is the reciprocal of the amount of time it takes for a single wavelength to pass a point (i.e. the rate at which the waves pass).
TRANSVERSE WAVE - A wave in which the particles of the medium move perpendicular to the wave.
LONGITUDINAL WAVE - A wave in which the wave energy's (& medium particle interaction) direction is parallel to the wave.
PERIOD (T) - The time needed for an object to complete a full cycle. The time taken for any particle to make one complete oscillation (one complete to-and-fro movement).
05-11-07
WAVE PULSE - A short length of a wave or a single oscillation.
PHASE - Where an oscillation is in its cycle, usually represented as a fraction of 360o, with 360o as a reference measurement for one complete cycle.
OSCILLATION - Same as vibration, a motion that repeats regularly, with the exception that an oscillation is generally a designed or favorable event whereas a vibration is not.
5-22-07
INFRA - Below, beneath, under -- often used as a prefix,
as in "Infrared" - meaning just below the visible light color "Red" of the EM spectrum in frequency and energy level.
ULTRA - A prefix from the Latin meaning beyond, on the other side, chiefly when joined with words expressing relations of place - as with "Ultraviolet" - meaning just above the visible light color "Violet" of the EM spectrum in frequency and energy level.
ROY G. BIV - A memory aid for the colors of visible light of the EM spectrum - inorder from the lowest frequency & lowest energy (red) to highest frequency highest energy (violet).
REFRACTION - The change of direction of a ray of light, sound, heat, or the like, in passing from one medium into another in which its wave velocity is different.
DIFFRACTION - The bending of waves, e.g. sound and light waves, around obstacles in their path.
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