Principles of Engineering – Unit 1.1 Mechanisms

Concepts 1. Engineers and engineering technologists apply math, science, and discipline-specific skills to solve problems. 2. Engineering and engineering technology careers offer creative job opportunities for individuals with a wide variety of backgrounds and goals. 3. Technical communication can be accomplished in oral, written, and visual forms and must be organized in a clear and concise manner. 4. Most mechanisms are composed of , , systems, and simple . 5. Mechanisms are used to redirect energy within a system by manipulating , speed, and distance. 6. Mechanical advantage ratios mathematically evaluate input work versus output work of mechanisms. Essential Questions 1. Why is it important to begin considering career paths during high school? 2. What career opportunities are available to match your specific interests? 3. What are some current applications of simple machines, gears, pulleys, and sprockets? 4. What are some strategies that can be used to make everyday mechanisms more efficient? 5. What are the trade-offs of mechanical advantage related to design? 6. Why must efficiency be calculated and understood during the design process?

Unit 1.1 – Mechanisms - Key Terms ABET The recognized accreditor for college and university programs in applied science, computing, engineering, and technology.

Actual Mechanical The ratio of the magnitude of the resistance and effort applied to a Advantage system.

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

Career A profession for which one trains and which is undertaken as a permanent calling.

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 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 the 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 rotates.

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

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

Idler 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 an 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 and turning at a third on a fulcrum.

Mechanism The structure of or the relationship of the parts in a , 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 .

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, the wheel and axle, the pulley, the inclined plane, the wedge, and the 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 for tightening by being driven into something.

Wheel and Axle Two different sized circular objects that are attached together and turn as one.