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Actual Mechanical Advantage

The ratio of the magnitude of the resistance and effort forces applied to a system.

Belt

A continuous band of tough flexible material used to transmit motion and power within a pulley system.

Chain

A series of usually metal links or rings connected to or fitted into one another and used to transmit motion and power within a sprocket system.

Effort Force

An external force applied to an object.

Efficiency

The ratio of useful energy output to the total energy input, or the percentage of work input that is converted to work output.

Friction

The resistance that one surface or object encounters when moving over another.

Fulcrum

The fixed point around which a lever rotates.

Gear

A circular toothed object used to transfer rotary motion and torque through interlocking teeth.

Ideal Mechanical Advantage

Ratio of distance traveled by the applied effort and resistance force within a system.

Idler Gear

A gear positioned between the driver and the driven gear used to change rotational direction.

Inclined Plane

A flat surface set at an angle (or incline) with no moving parts that is able to lift objects by pushing or pulling the load.

Lever

A rigid bar used to exert a pressure or sustain a weight at one point of its length by the application of a force at a second point and turning at a third on a fulcrum.

Mechanism

The structure of or the relationship of the parts in a machine or in a construction or process comparable to a machine.

Moment

The turning effect of a force about a point equal to the magnitude of the force times the perpendicular distance from the point to the line of action from the force.

Pitch

Distance between adjacent threads in a screw.

Pulley

A type of lever that is a wheel with a groove in its rim, which is used to change the direction or multiply a force exerted by a rope or cable.

Resistance Force

Impeding effect exerted by one material object on another.

Screw

An inclined plane wrapped around a cylinder, forming the path and pitch.

Simple Machine

Any of various elementary mechanisms including the lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Sprocket

A toothed wheel whose teeth engage the links of a chain.

Static Equilibrium

A condition where there are no net external forces acting upon a particle or rigid body and the body remains at rest or continues at a constant velocity.

Technical Communication

Creating, designing, and transmitting technical information so that people can understand it easily and use it safely, effectively, and efficiently.

Torque

A force that produces or tends to produce rotation or torsion.

Wedge

A substance that tapers to a thin edge and is used for splitting, raising heavy bodies, or tightening by being driven into something.

Wheel and Axle

Two differently sized circular objects that are attached together and turn as one.

Alternative Energy

Any source of energy other than fossil fuels that is used for constructive purposes.

Ampere

The unit of electric current in the meter-kilogram-second system of units. Referred to as amp and symbolized as A.

Biomass

Plant materials and animal waste used especially as a source of fuel.

Current

The net transfer of electric charge (electron movement along a path) per unit of time.

Electrical Energy

Energy caused by the movement of electrons.

Electricity

The flow of electrical power or charge.

Electromagnetic Induction

The production of electricity in conductors with the use of magnets.

Efficiency

The ratio of the useful energy delivered by a dynamic system to the energy supplied to it.

Energy

A fundamental entity of nature that is transferred between parts of a system in the production of physical change within the system and usually regarded as the capacity for doing work.

Energy Conversion

Changing one form of energy to another.

Fossil Fuel

A natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.

Generator

A dynamo or similar machine for converting mechanical energy into electricity.

Geothermal Energy

The use of heat from within the Earth or from the atmosphere near oceans.

Gravitational Energy

The state when objects are not yet in motion.

Induction

The production of an electric or magnetic state by the proximity (without contact) of an electrified or magnetized body.

Inexhaustible Energy

An energy source that will never run out.

Kinetic Energy

Energy which a body possesses by virtue of being in motion.

Nonrenewable Energy

A resource that cannot be replaced once used.

Parallel Circuit

A closed electrical circuit in which the current is divided into two or more paths and then returns via a common path to complete the circuit.

Potential Energy

The energy that a piece of matter has because of its position or nature or because of the arrangement of parts.

Power Converter

Changes one form of power to another.

Power Grid

A system that links electricity produced in power stations to deliver it to where it is needed.

Renewable Energy

A resource that can be replaced when needed.

Resistance

The opposition that a device or material offers to the flow of direct current.

Work

A result of a force moving an object a certain distance.

Turbine

A machine for producing power in which a wheel or rotor is made to revolve by a fast-moving flow of water, steam, gas, or air.

Power

The rate at which work is performed or energy is expended.

Rotor

The rotating member of an electrical machine.

Series Circuit

A circuit in which all parts are connected end to end to provide a single path of current.

Volt

The unit of potential difference symbolized as V.

Voltage

The potential difference measured in volts. The amount of work to be done to move a charge from one point to another along an electric circuit.

Alternative Energy

Any source of energy other than fossil fuels that is used for constructive purposes.

Ampere

The unit of electric current in the meter-kilogram-second system of units. Referred to as amp and symbolized as A.

Conduction

The transfer of heat within an object or between objects by molecular activity, without any net external motion.

Convection

Process by which, in a fluid being heated, the warmer part of the mass will rise and the cooler portions will sink.

Current

The net transfer of electric charge (electron movement along a path) per unit of time.

Electrical Energy

Energy caused by the movement of electrons.

Electricity

The flow of electrical power or charge.

Electromagnetic Energy

Energy caused by the movement of light waves.

Electrolysis

The process separating the hydrogen-oxygen bond in water using an electrical current.

Energy

The ability to do work.

Entropy

The function of the state of a thermodynamic system whose change in any differential reversible process is equal to the heat absorbed by the system from its surroundings divided by the absolute temperature of the system.

First Law of Thermodynamics

The law that heat is a form of energy, and the total amount of energy of all kinds in an isolated system is constant; it is an application of the principle of conservation of energy. Also known as conservation of energy.

Fuel Cell Stack

Individual fuel cells that are combined in series.

Heat

Energy in transit due to a temperature difference between the source from which the energy is coming and a sink toward which the energy is going.

Ohm

The unit of electric current in the meter-kilogram-second system of units. Symbolized as Ω.

Ohm's Law

States that the direct current flowing in an electric circuit is directly proportional to the voltage applied to the circuit.

Passive Solar Energy Collection

Systems that do not make use of any externally powered, moving parts, such as circulation pumps, to move heated water or air.

Product Development Life Cycle

Stages a product goes through from concept and use to eventual withdrawal from the market place.

Radiation

The process by which energy is transmitted through a medium, including empty space, as electromagnetic waves. This energy travels at the speed of light. This is also referred to as electromagnetic radiation.

R-value

The measure of resistance to heat flow.

Second Law of Thermodynamics

A general statement of the idea that there is a preferred direction for any process.

Temperature

A property of an object which determines the direction of heat flow when the object is placed in thermal contact with another object.

Thermal Equilibrium

Refers to the property of a thermodynamic system in which all parts of the system have attained a uniform temperature which is the same as that of the system's surroundings.

Thermodynamic System

A part of the physical world as described by its thermodynamic properties such as temperature, volume, pressure, concentration, surface tension, and viscosity.

Thermodynamics

The study of the effects of work, heat, and energy on a system.

U-value

A measure of thermal transmittance through a material.

Zeroth Law of Thermodynamics

A law that if two systems are separately found to be in thermal equilibrium with a third system, the first two systems are in thermal equilibrium with each other; that is, all three systems are at the same temperature. Also known as thermodynamic equilibrium.

Accuracy

The condition or quality of being true, correct, or exact; precision; exactness.

Consensus

A general agreement.

Cable

A strong rope, usually made of metal, designed to have great tensile strength and to be used in structures.

Centroid

The geometric center of an area.

Compression Force

A body subjected to a push.

Concurrent Force Systems

A force system where all of the forces are applied at a common point on the body or having their lines of action with a common intersection point.

Cross-Sectional Area

A surface or shape exposed by making a straight cut through something at right angles to the axis.

Direction

The direction of a vector is defined by the angle between a reference axis and the arrow's line of direction.

Fixed Support

A support that prevents translation and rotation in a beam.

Flange

A broad ridge or pair of ridges projecting at a right angle from the edge of a structural shape in order to strengthen or stiffen it.

Free Body Diagram

A diagram used to isolate a body from its environment, showing all external forces acting upon it.

Gusset

A plate or bracket for strengthening an angle in framework.

Joint

The connection points of members of a truss.

Magnitude

The absolute value of a number.

Member

Slender straight pieces of a truss connected by joints.

Method of Joints

A method of analysis of trusses which constructs free body diagrams of each joint and determines the forces acting in that joint by considering equilibrium of the joint pin.

Moment of Inertia

A mathematical property of a cross section that is concerned with a surface area and how that area is distributed about a centroidal axis.