# Glossary

1st Law of Thermodynamics

Any change in the internal energy of a system must in the process of exchanging heat, doing work, or both.

3rd class lever

a lever with the effort between the load and the fulcrum.

absolute zero

A lower limit of temperature corresponding to the minimum possible average kinetic energy of atoms and molecules.

acceleration

the change in velocity per unit time, the slope of a velocity vs. time graph

acceleration due to gravity

the rate at which an object changes velocity when gravity is the only force acting on the object

accurate

refers to the closeness of a measured value to a standard or known value

Achilles tendon

a tough band of fibrous tissue that connects the calf muscles to the heel bone

A process for which the heat transferred is zero (Q = 0).

air resistance

a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid

analyze

examine methodically and in detail the constitution or structure of information for purposes of explanation and interpretation

apparent weigh
apparent weight

the reading on a scale that is used to measure the weight of an object that is submerged in a fluid

approximation

a rough value obtained without making a measurement by using prior knowledge and assumptions.

Archimedes’ Principle

The upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid being displaced by the body

assumption

ignoring some compilation of the in order to simplify the analysis or proceed even though information is lacking

at rest

not moving

average speed

average rate at which distance was traversed, equal to total distance traveled within a time interval, divided by the time interval

average velocity

the average of all instantaneous velocities that occurred within a certain time interval, equal to the displacement divided by the time interval

Barriers

Objects, events, or conditions that hinder access.

bedrock

hard rock exposed or buried at the earth's surface

biased

prejudice in favor of or against one thing, person, or group compared with another, usually in a way considered to be unfair or inaccurate.

bipedal

(of an animal) using only two legs for walking

Bloom’s Taxonomy
Bloom’s Taxonomy

A framework for categorizing educational goals.

Blooms Taxonomy
BMI

Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. BMI can be used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual

buoyant  force
buoyant force

the upward force exerted by any fluid upon a body placed in it

cantilevered

any rigid structure projecting from a support, especially one in which the projection is great in relation to the depth of the structure

Carnot efficiency

the maximum theoretical efficiency that a heat engine could achieve when operating between two set temperatures, as permitted by the Second Law of Thermodynamics

center of gravity

a point at which the force of gravity on body or system (weight) may be considered to act. In uniform gravity it is the same as the center of mass.

center of mass

a point representing the mean (average) position of the matter in a body or system

center of mass kinetic energy

kinetic energy stored in the center of mass motion of a system, calculated using the total mass of the system and the center of mass speed

a specific method for unit conversion that is designed to aid in reducing mistakes.

chemical potential energy

energy stored in the bonds between atoms and molecules

coefficient of friction
Cognition

The mental action or process of acquiring knowledge and understanding through thought, experience, and the senses

compression

reduction in size caused by application of compressive forces (opposing forces applied inward to the object).

Computer modeling

using a computer program that is designed to simulate what might or what did happen in a situation

conclusion

a judgment or decision reached by reasoning and logic based on results provided by analysis of data

condensation

Process of vapor changing phase into a liquid.

constant

not changing, having the same value within a specified interval of time, space, or other physical variable

convection cell

cyclic fluid flow caused by natural convection

conversion factor

a number that relates two different units of measure for the same quantity and allows conversion between the two units

crust

the relatively thin layer of rock that makes up the outermost solid shell of our planet

data

collection of values measured during an experiment

density

relation between the amount of a material and the space it takes up, calculated as mass divided by volume.

derivation

a sequence of steps, logical, mathematical, or computational, combining one or more results to obtain another result

dew

water that condenses on cool surfaces at night, when decreasing temperature forces humidity to 100% or higher

displaced

pushed out of original position, typically in reference to fluid pushed out of the way by an object placed in the fluid, or an object being displaced from its equilibrium position

displacement

change in position, typically in reference to a change away from an equilibrium position or a change occurring over a specified time interval

displacement method

method for determining the volume of an object by measuring how much water it displaces

efficiency

ratio of work done to output energy in the desired to energy input required to do that work

effort

referring to a lever system, the force applied in order to hold or lift the load

elastic collisions

collisions that conserve kinetic energy

Elastic Modulus

Constant of proportionality relating a change in stress to a change in strain

elastic potential energy

energy stored in the deformation of materials

elastic region

the range of values for stress and strain values over which a material returns to its original shape after deformation

Empirical models

mathematical explanation of the relation between measured values that is used for making predictions

Energy

A quantity representing the capacity of an object or system to do work.

Energy pathway

the process of transferring chemical potential energy stored in food to useful work and thermal energy

Entropy

A measure of energy dispersion in a system.

equilibrium

a state of having no unbalanced forces or torques

external forces

Forces applied by objects not contained in the system being analyzed.

failure region

Region of the stress vs. strain curve beyond the yield point, where permanent deformation occurs.

Feedback

1) information about reactions to a product, a person's performance of a task, etc. which is used as a basis for improvement.

2) the modification or control of a process or system by its results or effects, e.g., in a biochemical pathway or behavioral response

final velocity

the value of velocity at the end of the time interval over which motion is being analyzed

force

any interaction that causes objects with mass to change speed and/or direction of motion, except when balanced by other forces. We experience forces as pushes and pulls.

force of gravity

attraction between two objects due to their mass as described by Newton's Universal Law of Gravitation

forced convection

transfer of heat due to the movement of fluid molecules driven by external factors other than thermal expansion.

free body diagram

a graphical illustration used to visualize the forces applied to an object

Free fall acceleration

The acceleration of an object when gravity is the only force acting on it. Equal to 9.8 m/s/s near the surface of Earth

friction

a force that acts on surfaces in opposition to sliding motion between the surfaces

fulcrum

the point on which a lever rests or is supported and on which it pivots

Glossary

The glossary feature includes rollover definition capability.

Gravitational Potential Energy

potential energy stored in the separation of objects attracted by the gravitational force

gravity passes
Green House Gas Effect

Elevation of Earth's temperature relative to the atmosphere-free condition caused differential absorption of UV, visible, and IR light by specific gases and particles present in the atmosphere.

Heat

An amount of thermal energy transferred due to a difference in temperature.

heat capacity

The amount of energy required to raise the temperature of an object by one temperature unit.

Heat death

the degradation of energy quality associated with a spontaneous processes.

histogram

A graph of relating how often a value falls within a certain range.

Hooke's Law

the force required to displace a material from its current shape is proportional to the displacement and the stiffness constant of the material

hydrostatic weighing

a technique for measuring the mass per unit volume of a living person's body. It is a direct application of Archimedes' principle, that an object displaces its own volume of water

Hyperthermia

The condition of having a body temperature well above the normal range.

hypothermia

The condition of having a body temperature well below the normal range.

hypothesis

a proposed explanation made on the basis evidence that can be supported or refuted by the result of experimentation

impulse

average force applied during a collision multiplied by the collision time

Impulse-Momentum Theorem

the change in momentum experienced by system is equal to the net force on the system multiplied by the amount of time that force is applied

inelastic collision

a collision for which kinetic energy is not conserved

internal energy

the total energy of all types stored within components that are internal to the system

irreversible

a process that is not a reversible process in which the system and environment can be restored to exactly the same initial states that they were in before the process

Isolated system

a system for which neither thermal energy or particles are allowed to leave or enter.

kelvin

SI unit of temperature

kinetic energy

energy stored in the motion of an object

kinetic friction

a force that resists the sliding motion between two surfaces

latent heat of fusion

the thermal energy required to melt a unit mass of a substance

latent heat of vaporization

Thermal energy input required to change a unit mass of liquid into vapor.

law

a statement, usually in the form of a mathematical equation, that summarizes, but not explains, the results of repeated experiments or observations that describe some aspect of the natural, usually within a certain range of application.

Law of Conservation of Energy

The net external work done on a system is equal to it's change in energy. If the net external work is zero, the system total energy cannot change, but energy may be transferred between different types within the system.

Law of Conservation of Momentum

The total momentum of an isolated system cannot change.

Learning management system

a software application for the administration, documentation, tracking, reporting, and delivery of educational courses, training programs, or learning and development programs

lever

a rigid structure rotating on a pivot and acting on a load, used multiply the effect of an applied effort (force) or enhance the range of motion

lever classes

There are three types or classes of levers, according to where the load and effort are located with respect to the fulcrum

linear region

linear region of the stress vs. strain curve

linear thermal expansion coefficient

Material property that relates the fractional change in length experienced by an object due to a unit change in temperature.

magnitude

the size or extent of a vector quantity, regardless of direction

mass

a measurement of the amount of matter in an object made by determining its resistance to changes in motion (inertial mass) or the force of gravity applied to it by another known mass from a known distance (gravitational mass). The gravitational mass and an inertial mass appear equal.

measurement error

Measurement Error (also called Observational Error) is the difference between a measured quantity and its true value. It includes random error (naturally occurring errors that are to be expected with any experiment) and systematic error (caused by a mis-calibrated instrument that affects all measurements)

measurement units

a unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement.

mechanical efficiency

efficiency in converting energy from the source form (thermal, chemical potential, electromagnetic) to one of the mechanical forms of gravitational potential energy, elastic potential energy, or kinetic energy.

mechanical energy

the total of the kinetic, elastic potential, and gravitational potential energy in a system

mechanical power

rate at which energy is transferred into mechanical energy

Melting

changing phase from solid to liquid.

Metacognition

awareness and understanding of one's own thought processes

metastable equilibrium

a state in which a slight disturbance results in a restoring force that maintains stability, but a sufficiently large disturbance moves the system into an unstable region (or different metastable region)

method of significant figures

using the number of digits provided in a measurement value to indicate the measurement uncertainty

metric prefix

a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit

model

a representation of something that is often too difficult (or impossible) to observe or display directly

momentum

mass multiplied by velocity

Splitting attention between more than one task at a time.

Natural convection

Transfer of heat due to fluid movement caused by thermal expansion of the fluid

nervous system

the network of nerve cells and fibers which transmits nerve impulses between parts of the body

net force

the total amount of remaining unbalanced force on an object

net torque

remaining unbalanced torque on an object

net work

the sum of all the works done by each force acting on a system

Newton

the SI unit of force. It is equal to the force that would give a mass of one kilogram an acceleration of one meter per second per second

Newton’s Law of Cooling

Observation that the rate of change of the temperature of an object is proportional to the difference between its own temperature and the environmental temperature

Newton's First Law of Motion

An object will not change it's motion unless acted upon by an external force.

Newton's Second Law of Motion

The net force on a system is equal to the system mass multiplied by the acceleration

Newton's Third Law of Motion

If object A exerts a force on object B, then object B also exerts an equal and opposite force on object A for the same amount of time

Newtons
non-conservative forces

forces that do non-conservative work, which is work that does not transfer energy only among kinetic and potential forms (mechanical energy)

normal force

the outward force supplied by an object in response to being compressed from opposite directions, typically in reference to solid objects.

null hypothesis

default position that there is no relation between two measured quantities

order of magnitude

designating which power of 10 (e.g. 1,10,100,100)

order of magnitude estimation

the process of approximating a value to obtain a result you expect to at least be within one order of magnitude of the correct answer.

origin

location where the position is zero

parallel

side by side, pointing in exactly the same direction, or having the same distance continuously between them

perfectly inelastic collisions

collisions in which objects start or end stuck together

perpendicular

at an angle of 90° to a given line, plane, or surface

Physical models

mechanistic explanation of how a physical system works

pivot

the central point, pin, or shaft on which a mechanism turns or oscillates

Position

the location of an object relative to a defined reference point

pounds

a unit of force equal to 4.44822 Newtons, or the the weight of a 0.4536 kg mass on Earth's surface

power

rate of energy conversion or transfer

power.

rate at which work is done

precision

refers to the closeness of two or more measurements to each other

preponderance

the quality or fact of being greater in number, quantity, or importance

principle

principles summarize rules created and followed by scientists when formulating hypotheses, designing experiments, analyzing results.

Principle of Energy Conservation

Energy cannot be created or destroyed, only transferred through the process of work

qualitative

describing what happens, but not how much happens

quantitative

describing what and how much happens

a unit of angle, equal to an angle at the center of a circle that produces an arc length equal to the radius

random error

random errors are fluctuations (in both directions) in the measured data due to the precision limitations of the measurement device. Random errors usually result from the experimenter's inability to take the same measurement in exactly the same way to get exact the same number

reactive force

a type of force supplied by an object in response to application of a different force on the object. Friction is a reactive force

Relative humidity

a measure of how many water molecules are in the vapor phase relative to the maximum number that could possibly be in the vapor phase at at a given temperature. A relative humidity of 100% means that no more water molecules can be added to the vapor phase.

resistance

the force working against the rotation of a lever that would be caused by the effort

restoring force

a force that tends to move a system back toward the equilibrium position

results

information acquired by analyzing data

rotational equilibrium

a state of having not net torque and no change in rotational motion

rupture

the sudden and complete failure of a material under stress

scientific method

a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses

scientific notation

a way of writing very large or very small numbers. A number is written in scientific notation when a number between 1 and 10 is multiplied by a power of 10.

significant figures

each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first nonzero digit

skinfold method

method for measuring body fat percentage using specially designed calipers to measure the thickness of skinfolds that are pinched from several specific locations on the body as inputs to empirical equations

specific gravity

the ratio of the density of a substance to the density of a standard, usually water for a liquid or solid, and air for a gas

specific heat

A material property that determines the amount of energy required to raise the temperature one mass unit of the material by one temperature unit.

Speed

distance traveled divided by time during which motion occurs

Spontaneous process

a process which occurs naturally on its own, without the need for work to be done in forcing it to happen.

spring constant

constant of proportionality between the displacement and the force causing the displacement in materials following Hooke's Law

stability

a measure of the displacement from equilibrium an object can experience and still move back toward equilibrium

stable equilibrium

a state in which a body tends to return to its original position after being disturbed

standard scientific (SI) units

a system of physical units ( SI units ) based on the meter, kilogram, second, ampere, kelvin, candela, and mole

static equilibrium

the state being in equilibrium (no unbalanced forces or torques) and also having no motion

static friction

a force that resists the tenancy of surfaces to slide across one another due to a force(s) being applied to one or both of the surfaces

static friction coefficient

proportionality constant relating maximum static frictional force to normal force

Stephan-Boltzmann Law

The total radiant heat energy emitted from a surface is proportional to the fourth power of its absolute temperature.

strain

the measure of the relative deformation of the material

stress

a physical quantity that expresses the internal forces that neighboring particles of material exert on each other

Study strategy

a thoughtful and specific process for self-directed learning.

support base

region defined by lines connecting points of contact with the supporting surface

system

A collection of objects to be analyzed. Forces between the objects are considered internal forces, while forces applied by objects outside the system are considered external forces.

Systematic errors

an error having a nonzero mean (average), so that its effect is not reduced when many observations are averaged. Usually occurring because
there is something wrong with the instrument or how it is used.

tension

the force that is provided by an object in response to being pulled tight by forces acting from opposite ends, typically in reference to a rope, cable or wire

test conditions

an item or event of a component or system that could be verified by one or more test cases, e.g., a function, transaction, feature, quality, attribute, or structural element

theory

an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method using accepted standard protocols

thermal energy

kinetic energy stored in the motion of microscopic particles

thermal equilibrium

a two systems are in thermal equilibrium when they do not exchange heat, which means they must be at the same temperature

thermal expansion

The increase change in volume of an object resulting from a change in temperature.

Thermal power

rate at which chemical potential energy is converted to thermal energy by the body, batteries, or heat engines. Also, rate at which thermal energy is converted to electrical energy by a thermal power plant.

Electromagnetic radiation spontaneously emitted by all objects with temperature above absolute zero.

thermometer

a device that measures temperature

tipping point

the point at which an object is displaced from a region of stable equilibrium

torque

the result of a force applied to an object in such a way that the object would change its rotational speed, except when the torque is balanced by other torques

torques
translational motion

motion by which a body shifts from one point in space to another (up-down, back-forth, left-right)

ultimate strength

maximum stress a material experiences before failure occurs

uncertainty

Amount by which a measured, calculated, or approximated value could be different from the actual value

under water weight

apparent weight when submerged in water

uniformly

in a way that is the same in all cases, across a defined set of space and times

unit analysis

act of ensuring that the units resulting from a calculation match the type of quantity calculated.

Universal Law of Gravitation

every particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers

unstable equilibrium

a state of equilibrium such that when the body is slightly displaced it departs further from the original position

useful work

work done by the body to transfer chemical potential energy to mechanical energy (kinetic energy, gravitational potential energy,  elastic potential energy)

vector

a quantity with both magnitude (size) and direction

vectors

a quantity having direction as well as magnitude

velocity

a quantity of speed with a defined direction, the change in speed per unit time, the slope of the position vs. time graph

volume

a quantity of space, such as the volume within a box or the volume taken up by an object.

Watts

Unit of power. Equal to Joules per second

weight

the force of gravity on on object, typically in reference to the force of gravity caused by Earth or another celestial body

wind chill effect

Increase in rate of heat loss from objects that are warmer than air caused by the flow of air across the object surface.

Work

A quantity representing the effect of applying a force to an object or system while it moves some distance.

work-energy principle

the change in kinetic energy of an object or system is equal to the net work done on the object or system