Fundamentals of Engineering (100 Questions) PDF

Fundamentals of Engineering (100 questions) History of Engineering 1957: Sputnik was the first satellite to orbit the Earth and send back signals from space. April 1961: Vostok-1 was the first manned spaceflight in history with Soviet cosmonaut Yuri Gagarin, making him the first human to cross into...

Fundamentals of Engineering (100 questions) History of Engineering 1957: Sputnik was the first satellite to orbit the Earth and send back signals from space. April 1961: Vostok-1 was the first manned spaceflight in history with Soviet cosmonaut Yuri Gagarin, making him the first human to cross into outer space. May 1961: Alan Shepard was the first American astronaut to fly into space. 1963 – 1972: The Apollo program was designed to land humans on the Moon and bring them safely back to Earth. The Apollo missions took about three days to reach the moon. 1969: Man first landed on the moon, and Neil Armstrong was the first astronaut to walk on the moon. 1981-2011: The space shuttle program. The primary function of the space shuttle was to transport astronauts to space and to help construct the international space station. 2004: SpaceShipOne won the X prize as the first private company to put a man into space. Engineering Careers STEAM stands for Science, Technology, Engineering, Arts, and Mathematics. Engineers use STEAM along with tools and materials to solve problems for mankind. There are many different types of engineers. Electrical Engineers design electrical power systems. Computer engineers use electrical engineering and coding to design computer hardware and software. Mechanical engineers design power-producing machines that manipulate torque, speed, energy, and fluids using gears, pistons, and generators. Aerospace Engineers design systems for aircraft. Civil Engineers design bridges, roadways, and dams. Chemical Engineers design large-scale processes that convert chemicals, raw materials, living cells, microorganisms and energy into useful forms and products. Manufacturing Engineers refine raw materials to create products using automated machines and assembly techniques to mass produce products. Engineering Design Process 1. A sample design process looks like this:  Define the problem  Identify Criteria and Constraints  Research, Brainstorm, Select Solutions  Design and Build  Test, Redesign, and Rebuild  Final Product for implementation Materials and Processes Hardwoods and Softwoods: There are two main types of wood: softwoods and hardwoods. Most softwoods have a lower density than most hardwoods. Softwood is cheaper than hardwood and used to make different types of plywood and some furniture. Examples of softwood trees are cedar, Douglas fir, pine, spruce. Hard wood is harder and more durable, and it can range in hardness. Balsa is actually a hardwood but on the softer end of the hardwoods. Hardwood is also more expensive and are used for furniture, doors, flooring, and decks. Examples of hardwood trees include poplar, ash, maple, and oak. Hardwoods come from deciduous trees, and softwoods come from coniferous trees. Deciduous trees are trees that lose their leaves seasonally. Coniferous trees are trees whose leaves are either small and needle-like or scale-like and most stay green all year around (evergreen) Density is a measure of how heavy an object is for a given size, i.e. the mass of material per unit volume. Aluminum and Magnesium have lower densities. Titanium, gold, steel, tungsten, lead, and platinum have higher densities comparatively. See table below. Wood veneer refers to thin slices of wood, usually thinner than 3 mm (1/8 inch), that typically are glued onto core panels (typically, wood, particle board or medium-density fiberboard) to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are mainly cosmetic and used to cover cheaper looking woods. See photo Concrete is used for the foundations of houses. See photo below Framing lumber is used to build wall framing in houses. See photo below. Plywood is typically used to cover a roof before shingles are added due to its water resistance. See photo below. Most homes now are built using dimensional lumber such as a 2x4, concreate, and plywood. Specific strength is a material's strength (force per unit area at failure) divided by its density. It is also known as the strength-to-weight ratio or strength/weight ratio. Any material that is strong AND light has a favorable Strength/Weight ratio. Materials such as Aluminum, titanium, magnesium, Carbon and glass fiber, high strength steel alloys all have good strength to weight ratios. Carbon Fibre is long thin strands mostly made from carbon atoms which are bonded together in microscopic crystals. The crystal is aligned which makes them incredibly strong. The fibre is woven together and then formed. See photos below. The photo to the right is a comparison between a steel pipe (silver) and a carbon fibre pipe (black). Carbon fibre is best suited for areas that require a higher stiffness and strength. While carbon fibre offers the best strength and rigidity to weight in the industry; it is also generally the most expensive of reinforcements. This is the main reason we don’t have more products made of Carbon fibre. Carbon fibre is also much more straightforward to cut, sand and machine in comparison to Kevlar, which requires specially made drill bits once laminated. That said, Kevlar offers a better abrasive strength than carbon fibre, which is why it is commonly associated with bulletproof vests. The photo below shows a deformed bullet after impacting the Kevlar in a bullet proof vest. Titanium 76, Titanium Alloy 260, Magnesium Alloy 158 Alloys are a mixture of two or more metals to create a metal with different properties. Brass is a metal alloy made of copper and zinc. Like all other kinds of steel, stainless steel is an alloy made primarily from iron and carbon in a two-step process. For many years (about 80) it has been known that adding chromium and nickel (the nickel is not essential but the chromium is essential) to iron makes a steel that does not rust (it is stainless). The chromium in the steel forms a very thin layer of oxide that prevents the iron from rusting. Rust is caused by oxidation. All metals, with the exception of the precious metals, will oxidize when exposed to oxygen and an electrolyte (i.e. atmospheric moisture). It is a chemical reaction of the metal surface with the oxygen present in the air that causes some of the metal to corrode (or oxidize) and form the respective metal oxide on the surface. In some metals such as steel, the corrosion products formed are very visible and loose. Everyone has observed the red color of iron oxide (rust) seen on improperly protected steel products. The red rust formed is generally scaly and loose and easily falls away exposing more and more basis material to the environment. Material Hardness. The Metals Handbook defines hardness as "Resistance of metal to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper, or to resistance to scratching, abrasion, or cutting. It is basically a measure of how much a material resists changes in shape. Hard things resist pressure. Some examples of hard materials are diamond, boron carbide, quartz, tempered steel, ice, granite, concrete. Quenching is a process most commonly used to harden steel. Quench hardening is a mechanical process in which steel and cast iron alloys are strengthened and hardened. This is done by heating the material to a certain temperature, depending on the material. This produces a harder material by either surface hardening or through-hardening varying on the rate at which the material is cooled. Adding carbon to steel will also increase its hardness. The photo below shows hot metal being rapidly cooled “quenched” with water. Sintering: Powder metallurgy processes use sintering to convert metal powders and other unique materials into end-use parts. Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Examples of pressure-driven sintering are the compacting of snowfall to a glacier, or the forming of a hard snowball by pressing loose snow together. There are also laser sintering 3d printers. Selective laser sintering is a powder-based 3D printing technology that uses a laser to fuse material layers into a final part. These types of 3D printers are capable of printing metal components. When a metal is described as “ferrous”, it means that it has a significant amount of iron in its composition. Ferrous metals are magnetic. Most plastic in use today comes from hydrocarbon molecules derived from crude oil, natural gas and coal – fossil fuels. Plastics are polymers. A polymer is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. A thermoplastic is a plastic material, a polymer, which becomes pliable or moldable above a specific temperature and solidifies upon cooling. Thus, thermoplastics may be reshaped by heating and are typically used to produce parts by various polymer processing techniques such as injection molding, compression molding, and extrusion (Acrylic, Polycarbonate, Teflon). Thermoplastics like polycarbonate become soft when heated and become opaque (white) after being heated and deformed. Arsenic, Mercury, and Asbestos are dangerous materials that are not safe to touch. Material Testing. Materials are tested to failure to determine different material properties like strength, stress, strain, and elasticity. The material usually gets pulled apart till fracture by a stress analysis machine. In ductile fracture, extensive plastic deformation (necking) takes place before fracture. The terms rupture or ductile rupture describe the ultimate failure of ductile materials loaded in tension. Rather than cracking, the material "pulls apart," generally leaving a rough surface. Lab Safety Congress created the Occupational Safety and Health Administration (OSHA) to assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education, and assistance. When in a work environment, all injuries need to be reported to your supervisor even non- serious, minor injuries. To minimize injury, always wear the appropriate attire. Loose clothing, ties, jewelry, and long hair that is not tied back can be unintentionally caught when working with power tools. The best thing to wear when working with power tools is a short sleeved shirt. The best type of footwear to wear while working in a workshop or manufacturing area are work boots. Safety colors in a workshop or manufacturing facility:  Red = Danger/emergency and fire equipment  Yellow = Caution - walkways, railings, trip hazards, and machine clearance areas  Purple = Radiation Hazards  Orange = Warning - dangerous machinery parts, safety guards, and pinch points  Blue = warning against starting or moving equipment under repairs or broken down.  Green = Safety designates location – (first aid stations) Power Tool Safety Always wear safety glasses while operating power tools. Always unplug power tools before making any adjustments. Always stand at least 3 feet away from someone who is using power tools. When using the bandsaw, make sure to keep guards in place at all times. The blade guard should be from 1/8 to 1/4 inch above stock. Keep hands away from blade and do not open upper or lower bandsaw doors while blade is in motion. Maintain a balanced stance in front of the machine and keep your body under control at all times; do not overreach. The teeth on the blade of a properly installed bandsaw should point downward in the direction of blade travel. A relief cut should be used when cutting curves with a band saw. This allows pieces of material to fall away while cutting the curves which puts less strain on the blade and you while directing the blade the around curves. Bench Belt Sander: The belt sander rotates a coarse belt at a certain rpm to sand down rough surfaces. A “stop” on a bench belt sander keeps the sander from throwing the stock off the belt and makes it easy for you to hold the stock in place while sanding. A disk sander is used for hand held directed sanding and smoothing. The disk of the sander is removable and replaceable. If the disk of a sander ever comes loose, you should stop immediately, unplug the sander, and then tighten or replace the sanding disk. The drill press is used to drill holes of certain sizes into material. There are different sized drill bits that you can use to make different sized holes. The chuck key is used to change drill bits. Insert bit into drill chuck and tighten with the chuck key. Remove chuck key from the drill chuck before starting the drill press. DO NOT leave chuck key in chuck while operating machine. This can cause the drill bit to fall off while spinning. Always clamp the stock down to the drill table when using a drill press. If you don’t use the clamp, your stock could move or spin with the drill bit. Engineering Drawings Engineers document their work in engineering notebooks. The engineering notebook is a legal document that is used to patent activities. All entries in an engineering notebook must be written in pen, and all pages must be numbered, signed, and dated. Sketches must have all parts labeled and have a description. Engineers often create isometric projections/sketches to visually represent a 3-dimensional view of an object. They also use a scale factor when making sketches to help visualize the actual size of an object relative to other objects. A scale factor is a number which scales, or multiplies, some quantity. In the equation y = Cx, C is the scale factor for x. For example, doubling distances corresponds to a scale factor of two for distance, while cutting a cake in half results in pieces with a scale factor of one half. The scale/size factor helps you solve all the other unknown size factors of a scale model. Engineering drawings can also be broken down into different object views depending on the information that needs to be communicated. Below is an example of a broken view. You can use a broken (or interrupted) view in a drawing to make it possible to display the drawing view in a larger scale on a smaller size drawing sheet. A section view is a view used on a drawing to show an area or hidden part of an object by cutting away or removing some of that object. Alternate Position Views indicate the range of motion of an assembly component by showing it in different positions. Engineering Drawing (IED) examples:  2 Orthogonal projections Sometimes contractors and engineers have to change their initial design plans during construction, so as-built drawings need to be made. As-builts are a revised set of drawings submitted by a contractor upon completion of a project or a particular job. They reflect all changes made in the specifications and working drawings during the construction process, and show the exact dimensions, geometry, and location of all elements of the work completed under the contract. Equations (Math problem solving) 1. Distance = Velocity x Time (d = vt) 2. Velocity = Distance / Time (v = d/t) 3. 0.00000009876 m = 98.76 nm = 0.09876 um  4. If you received three full time job offers, one for $13 per hour, one for 1,500 per month, and one for $28,500 per year, which job should you take if salary was your only consideration? 5. Alex rode his bike 900 miles and he carried a spare tire on the trip. To provide equal wear on all 3 tires, he changed his tires while traveling. How many miles of wear did each tire accumulate? 6. Which temperature is hotter? 260K, 70C, 40F Below are the only formulas that will be given to you. Business Ethics What does it mean to be ethical? Ethical: being in accordance with the rules or standards for right conduct or practice, especially the standards of a profession. Fundamentals of Mechanical 1. Spur gears (VEX gears – the ones we use in class) are used for speed reductions and increases, motion sync, and torque increases and reductions. 2. Gear Ratio Practice 3. Water boils at 212 degrees F and at about 100 degrees C. 4. A thermal system is a multipart assembly of coupled components (some of them thermal), showing a common structured behavior; e.g. a refrigerator is a combination of pipes, compressor, electric motor, heat exchangers, valves, insulation, casing, doors, lamp, etc., interacting to a common goal of cold production within. 5. The motion of atoms and molecules creates a form of energy called heat or thermal energy which is present in all matter. 6. An air conditioner can output 11,000 BTU per hour. How many kilowatts is this equal to? (1BTU/h = 0.000293KW) – This conversion is given to you. 7. How much power must a 12V battery provide to drive a 25 ohm load? (V=IR and P=VI) – These equations are given to you on this part of the exam, but they are not given to you on the electrical part of the exam. 8. Newton’s Laws of Motion:  Newton's first law of motion says that an object in motion stays in motion and an object at rest stays at rest, unless acted upon by an outside force. So, something that is moving keeps moving until something else stops it. (law of inertia)  The second law explains how the velocity of an object changes when it is subjected to an external force. For an object with a constant mass m, the second law states that the force F is the product of an object's mass and its acceleration a: F=m*a  The third law states that for every action (force) in nature there is an equal and opposite reaction. The third law can be used to explain the production of thrust by a jet engine.  9. Potential and Kinetic Energy PE = mgh KE = 1/2mv2 10. Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. It acts in the opposite direction of movement. Fundamentals of Electrical 1. Series and Parallel Circuits 2. Electrical schematics are helpful for troubleshooting. The components are represented with standard symbols that show the connection between components. Electrical schematics do not show an accurate distance and scale of the components of the circuit. 3. Series Circuit Characteristics: The current through each component is the same as the total current. The sum of the voltage drops across all components are equal to the total voltage. 4. Parallel Circuit Characteristics: The voltage across each component is the same as the total voltage. The sum of the current in each branch in a parallel circuit is equal to the total current in the circuit. 5. In direct current (DC), the electric charge (current) only flows in one direction. Everything that runs off of a battery, plugs in to the wall with an AC adapter, or uses a USB cable for power relies on DC 6. Electric charge in alternating current (AC) changes direction periodically. Home and office outlets are almost always AC. This is because generating and transporting AC across long distances is relatively easy. 7. Current is measured in amperes, Voltage is measured in volts, and Resistance is measured in ohms. 8. A multi-meter can measure Voltage, Amperage, and Resistance.  9. Batteries in Series and Parallel Fundamentals of Robotics Systems 1. Robotics arm parts 2. A holonomic drive base has 3 degrees of freedom – forwards and backwards, side to side, and rotate left and right. 3. A robot’s microcontroller (cortex) runs the robot and coordinates all control signals coming in from sensors and going out to the robot’s motors. It is the brain of the robot. 4. Motor controllers send control signals from the microcontroller which vary the motor voltage. We use them in class to speed up, slow down, reverse, and stop the motors. 5. Robots use autonomous programming and a microcontroller to run without human control. Fundamentals of Aerospace 1. Airfoil: Without getting too in depth. The basic idea is that the air on top of the foil (plane wings) travels faster than the air on the bottom. Bernoulli's Principle states that an increase in fluid velocity results in a decrease in pressure and vice versa, so the pressure on top of the foil is lower than on the bottom. This causes lift. Fundamentals of Manufacturing 1. Coordinates are usually specified in this order when using coordinate programming or CAM: (x,y,z) 2. Absolute coordinates refers to a Cartesian System that uses X, Y, and sometimes a Z-axis to establish a point some distance from a common origin. For example, the picture shows an origin point of '0,0' and the absolute coordinate from that point is '8,7' making it 8 along the X-axis and 7 along the Y-axis. 3. Relative coordinates are locations defined by their distance from a given point. 4. The snap grid feature in CAD modeling software contains points that the cursor automatically moves to during sketching. 5. 3D printing is an additive process that is used for rapid prototyping (testing an idea fast). It adds material until it creates the object in a CAD model. 6. CNC machining is a subtractive process. It starts with a block of material and then cuts around the block until it creates the object in a CAD model. 7. Molding is the preferred process for manufacturing plastic parts. Injection molding is used to create many things such as electronic housings, containers, bottle caps, automotive interiors, combs, and most other plastic products available today. With injection molding, melted resin is injected into a hollow mold until it is completely filled. The injection mold is held together under intense pressure, sufficient enough for every part of the interior to be filled with high pressure molten plastic resin. Blow molding is used to produce plastic water bottles. With blow molding, a plastic tube is heated and filled with air until it essentially becomes a balloon of hot plastic called a “parison”. A mold is then clamped around this, trapping the plastic while air continues to fill the parison into the shape of your part. 8. The first automobile to be mass produced in the United States was the 1901 Curved Dash Oldsmobile, built by the American car manufacturer Ransome Eli Olds (1864-1950). Olds invented the basic concept of the assembly line and started the Detroit area automobile industry 9. Quality control (QC) is a process through which a business seeks to ensure that product quality is maintained or improved.... This is done by training personnel, creating benchmarks for product quality, and testing products to check for statistically significant variations.