ENGINEERING STUDY GUIDE FOR INTERIM
If a mass that weighs 15 kg is held at a height of 3 m, what is its potential energy? Potential energy = m*g*h
15 kg*3 m * 9.8 m/s^2
Be able to give differences in hydraulic and pneumatic systems
2 similarities: They all have the four primary components Both are pressurized fluids 2 differences: Hydraulics are closed systems and pneumatics are open system Hydraulics are used for HEAVY work, pneumatics are used for light weight work Hydraulics use liquid and pneumatics use air Hydraulics operate at high pressure, pneumatics operate at low pressure Pneumatic is generally safer and cleaner than hydraulics
Discuss the environmental concerns related to (2) types renewable energy.
5 Watt*hour per day * 365 days= 1825 watt*hr/year 1825 watt*hr/year/1000= 1.825 KWhr 1.825 KWhr * $.20/KWhr = $0.37
Be able to define a fluid power system
A force is applied to a fluid (air or liquid) which transfers its energy to a mechanical device to perform work
Identify the 5 steps in the engineering design process.
A.Identify the problem B. Research/brainstorm C. Prototype D. Test E. Document the FINAL Solution (Outcome documentation, customer facing)
Identify the 3 primary components of a Bill of Material.
A.Quantity B. Name of the part C. Material D. Part Number
Understand and explain the four primary components in a hydraulic or pneumatic system
A.Reservoir Pump/Compressor Valves Actuator
1. Law of Inertia
An object in motion stays in motion until acted on by a force.
The small piston in a hydraulic lift has an area of 30 cm2. A mass of 4 kg is applied to the small piston. What is the area of the piston if the resulting output force of the large piston is 90 N? What is the radius?
Answer = 69 cm^2 90*30 / (4*9.8)
A barber raises his customer's chair by applying a force of 200N to a hydraulic piston of area 0.01 m^2. If the chair is attached to a piston of area 0.1 m^2, what is the maximum mass the chair can handle? Assume the chair itself has a mass of 5 kg.
Answer: m = 199 kg 200*.1 / .01 F = 2000N m = 204kg - 5kg
What are some subfields of chemical engineering?
Biomolecular / pharmaceutical Energy Materials and Polymers
Explain the difference in computer science and computer engineering
Computer Science = SOFTWARE Computer Engineering = HARDWARE
Define Reverse Engineering and explain 3 reasons why reverse engineering is important.
Define: Taking an object apart to analyze construction: Learn/Know more about it Improve/make it better Fix it repair Remake it if old documentation doesn't exist Remake it for obsolete parts
If energy costs $0.20 per kWh, how much are you saving by using solar power to charge a phone from 0-100% every day for a year?
E= P*t E= 5Wh t=? P= 0.6 watts 8.3 hours 4 panels
Solve problems related to thermodynamics and phase diagrams.
Energy transfer and phase changes: Q = mcΔT and Q = mH
Ms. Begat's car, which weighs 1,000 kg, as it has run out of gas. Ms. Begat is trying to push the car to a gas station, and she makes the car accelerate at 0.05 m/s^2. Calculate how much force Ms. Begat is applying to the car. Show work to receive credit.
F = ma 1000 kg * .05 m/s^2 = 50 Newtons Units for Force = NEWTONS = kg*m/s^2
3 (Action - reaction law)
For every action there is an equal and opposite reaction
2. Law of Conservation of Energy
Force equal mass times acceleration
Be able to identify objects that use hydraulics and objects that use pneumatics
Hydraulics: bulldozer, elevator, brakes, planes Pneumatics: dentist drill, office computer chair, door stopper
Name one renewable and one non-renewable energy source and one fact about each.
Hydroelectric: uses water flow to turn a generator to create electrical flow Natural Gas: a fossil fuel refined from petroleum. Most common energy source in LA
Justin Timberlake has taken up the sport of competitive diving. He is at the top of the diving platform and then launches himself towards the pool. He had a kinetic energy of 12,000 J just prior to hitting the pool. If Justin's mass is 85 kg, then what is his speed?
KE = (m*v^2)/2 12,000 J = 85*v^2/2
Are assembly lines generally more efficient when you produce small quantities of a product or large quantities of a product?
LARGE because your start and end process is spread out. Setup time is spread out.
Specific Heat
Lower - Faster Higher - Slower
Explain the concept of line balancing as it relates to assembly line efficiency.
Making sure there are no bottlenecks, reduce idle time Break up the tasks so that each station takes the same amount of time.
Use the information below of your solar panel. Max Current - 120 mA Average Voltage - 5V What is the maximum power the solar panel can generate?
Max Current - 120 mA Average Voltage - 5V
If else statements are ..
NOT infinite loops
Recognize and use Pascals Law.
P1=P2 F1/A1 = F2/A2
If it requires 5 Wh of energy to fully charge a cell phone, how long will it take to charge? Extra: How many solar panels would you need to wire in parallel to charge in only 2 hours?
P=I*V I=0.12 0.6 Watts
Describe the characteristics, differences and similarities of parallel and series circuits
Parallel - multiple pathways if one bulb breaks, the rest stay on if I add more light bulbs, the others stay the same brightness Likely to overheat Series Single pathway If one bulb breaks, they all go out If you add more light bulbs, the others get dimmer Less likely to overheat
Identify the parts of a circuit diagram
Power source, resistors, LED
Identify when you should use a series circuit versus a parallel circuit.
Series: robotics circuits--If one piece isn't working you don't want others to work Parallel: when you don't want systems to rely on each other to work--most things are wired in parallel
Explain what it means to debug your computer program
Syntax - spelling error / typo Logic - How the program thinks
List two advantages of using a breadboard during circuit design.
Test without having to solder Very understandable Easy to fix/change Parts are not damaged by soldering and unsoldering
Define Energy. Explain how energy and work are related.
The ability to do work. Energy cannot be created or destroyed. The amount of work you do depends on the amount of energy you have.
In a hydraulic system, understand and explain the trade off between mechanical advantage and distance that the piston travels.
The larger the piston, the larger the mechanical advantage, but the shorter the distance the piston can travel.
What are unit operations? List the general types of operaters.\ Unit operations make up a process flow diagram and show the steps needed to have input and output
Unit operations make up a process flow diagram and show the steps needed to have input and output Combination: blender, mixer, percolation Separation: distillion, crystallization, centrifugal separation, filtration Heat Transfer: heat exchanger, dryer, evaporation Fluid Flow: Fluid transportation (via pumps, suction, and gravity through pipes) Mechanical Processes: Solid transportation (via conveyor or other), crushing, sifting Thermodynamic processes: Gas liquefaction (condensation), refrigeration (changing the state), compression.
IN Petroleum engineering, describe the differences from upstream, midstream, and downstream.
Upstream finds and produces crude oil and natural gas - exploration and production Midstream processes, stores, markets and transports commodities such as crude oil, natural gas, natural gas liquids (NGLs, mainly ethane, propane and butane) and sulphur. Downstream includes oil refineries, petrochemical plants, petroleum products distributors, retail outlets and natural gas distribution companies.
How do you calculate the relative humidity?
Use a chart to look up the dry bulb temperature vs the difference between the wet and dry bulbs
Identify the 6 types of simple machines. Be able to calculate the mechanical advantage of each.
pulley (length/height) screw wedge Inclined plane lever Wheel and axle
Pseudocode
uses short english phrases to explain tasks
