Lesson 1.1 Mechanisms - key terms
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Actual Mechanical Advantage: The ratio of the magnitude of the resistance and effort forces applied to a system Belt: A continous band of tough flexible material used to transmit motion and power within a pulley system Career: A profession for which one trains and which is undertaken as a long-term vocation Chain: Series of usually metal links or rings connceted 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. |
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. |
LESSON 1.2 Energy sources - KEY TERMS
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. Environmental Protection Agency An organization that works to develop and enforce regulations that implement environmental laws enacted by Congress. 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. |
Ohm
The unit of electric resistance 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. 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. |
Lesson 1.3 Energy application - key terms
Active Solar Energy Collection
A type of system that uses circulating pumps and fans to collect and distribute heat. 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. Kelvin A unit of absolute temperature and symbolized as K. Formerly known as degree Kelvin. Line of Best Fit A straight line that best represents all data points of a scatter plot. This line may pass through some, all, or none of the points displayed by the scatter plot. Also referred to as a Trend Line or Regression Line. |
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 Lifecycle 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. 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. 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. 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. 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. |