Engineering and Technology Flashcards

An engineering team is developing a new water filtration system for a remote community. Their prototype successfully removes 99.9% of bacteria but has a very slow flow rate. The community has also expressed a strong preference for a system built with locally sourced, sustainable materials. When optimizing the design, the team finds that increasing the flow rate reduces bacterial removal efficiency to 98%, while using local materials increases the cost by 20%. Which of the following best represents the team's primary challenge in this advanced stage of the design process?

Answer: Balancing prioritized criteria and making trade-off considerations.

This scenario describes a classic engineering challenge where multiple criteria (effectiveness, flow rate, sustainability, cost) are in conflict. The team must weigh the importance of each factor and make informed compromises, which is the essence of making trade-off considerations to refine a solution for a complex real-world problem.

A student team is testing the effectiveness of different airfoil designs for a model airplane to maximize flight time. They conduct their tests outdoors on different days. Their data shows that Design B, tested on a calm, sunny day, had a significantly longer flight time than Design A, which was tested on a windy, overcast day. What is the most significant flaw in their investigation's design?

Answer: Failure to control for confounding variables in the testing environment.

The difference in weather conditions (wind, sun/overcast affecting air density/thermals) between the tests is a major confounding variable. It introduces factors other than the airfoil design that could explain the difference in flight times. A valid investigation must control for such variables to ensure that the results are due to the factor being tested.

An engineering firm is tasked with designing a new traffic control system for a busy intersection. They create a sophisticated computer simulation to model traffic flow. Which of the following procedures would be the most effective way to ascertain the simulation's reliability before proposing it to the city?

Answer: Testing the model using historical traffic data from the intersection and comparing the simulation's output with the real-world outcomes.

The most direct and effective method to test a model's reliability is to validate it against known, real-world data. By inputting historical data, the engineers can see how well the model's predictions match what actually happened, providing a strong measure of its accuracy and reliability for future predictions.

A team is developing an automated irrigation system for a greenhouse. Their goal is to maintain optimal soil moisture while minimizing water usage. After analyzing test data, they identify a specific component—a moisture sensor—that provides inconsistent readings when the temperature exceeds 35°C, leading to system failure (either over or under-watering). What is the next logical step in optimizing this system?

Answer: Focusing on improving or replacing the identified failure point in the system.

The process of optimization involves analyzing data to identify specific features or components that are limiting performance. The team has successfully identified a failure point (the sensor's unreliability at high temperatures). The next step is to manipulate this variable by refining, improving, or replacing that specific component to improve overall system performance.

Which of the following represents the most complex application of modeling in the engineering design process?

Answer: Developing a computational model that allows for the manipulation of multiple interacting variables to predict system behavior under different conditions.

Developing a computational model that allows for manipulating interacting variables represents the most complex application. This type of model is not just a static representation; it's a dynamic tool used to predict phenomena, analyze the entire system, generate data, and identify potential failure points without building numerous physical prototypes.

A company proposes a new, highly efficient solar panel for residential use. In their proposal, they present valid and reliable data showing a 5% increase in energy conversion over competitors. However, the evaluation of their design solution is not complete until which of the following is also considered?

Answer: Economic, societal, and environmental factors like manufacturing cost, lifespan, and the impact of material disposal.

According to the AZSCI standards, evaluating a design solution for a real-world problem requires more than just technical performance. It involves a holistic assessment based on scientific knowledge, empirical evidence, and logical arguments regarding relevant factors, which explicitly include economic, societal, and environmental considerations.