Engineering Design Process Applied to Science Problems
Use criteria, constraints, testing, and iteration to solve real science challenges
Engineering Design Process Applied to Science Problems
Use criteria, constraints, testing, and iteration to solve real science challenges
Science - Grade 9-12
- 1
A town needs to reduce nitrate levels in a small lake caused by fertilizer runoff. Identify the problem, one design criterion, and one constraint for an engineering solution.
A criterion describes what success looks like. A constraint describes a limit on the solution.
The problem is that fertilizer runoff is increasing nitrate levels in the lake. One design criterion is that the solution must lower nitrate concentration to a safe level. One constraint is that the solution must fit within the town's budget or avoid harming local wildlife. - 2
A student team wants to design a low-cost water filter for hiking. List three scientific questions they should research before building a prototype.
They should research what contaminants are common in natural water sources, which filter materials remove those contaminants, and how flow rate affects filtration effectiveness. These questions connect scientific knowledge to the design choices. - 3
A prototype solar oven reaches 65 degrees Celsius on a sunny day, but the goal is 90 degrees Celsius. Name two possible redesigns and explain how each could increase the oven's temperature.
Think about increasing energy input and decreasing energy loss.
The team could add reflective panels to direct more sunlight into the oven, which would increase incoming energy. They could also improve insulation, which would reduce heat loss to the surroundings and help the oven reach a higher temperature. - 4
A design team is creating a sensor system to warn people about poor indoor air quality. Write two measurable criteria that could be used to judge whether the system works well.
One measurable criterion is that the sensor must detect carbon dioxide levels within 50 parts per million of a calibrated reference sensor. Another criterion is that the alarm must activate within 10 seconds after pollutant levels pass the safety threshold. - 5
A group builds three wind turbine blade designs and measures the electrical output in watts. Design A produces 2.1 W, Design B produces 3.4 W, and Design C produces 2.9 W under the same wind speed. Which design best meets the goal of maximizing electrical output, and what should the team do next?
The best design is not always chosen from one test alone. Engineers verify results and check trade-offs.
Design B best meets the goal because it produces the highest electrical output at 3.4 W. The team should repeat the test, collect more data, and examine whether Design B also meets other constraints such as durability, cost, and safety. - 6
Explain why engineers usually build and test a prototype before constructing a full-size final design.
Engineers build and test prototypes because prototypes reveal problems, provide data, and allow improvements before the final design is built. This reduces risk, saves resources, and helps the final design meet the criteria and constraints. - 7
A class is designing a device to protect a raw egg during a 3-meter drop. The criteria are that the egg must not crack and the device must have a mass under 150 grams. The constraints are that only paper, tape, string, and cotton balls may be used. Propose a design and explain how it addresses the criteria and constraints.
Use science ideas such as force, impact time, and energy transfer.
A good design could use a paper frame to spread out the force, cotton balls around the egg to absorb impact, and string to hold the egg in the center. This design uses only the allowed materials, can be kept under 150 grams, and reduces the force on the egg during impact. - 8
A student says, "Our first design failed, so the project is over." Write a response explaining how failure is used in the engineering design process.
Failure is not the end of an engineering project. It gives information about what did not work, so the team can identify weaknesses, revise the design, and test an improved version. Iteration is a normal part of engineering. - 9
A team is designing a barrier to reduce beach erosion. They must protect the shoreline but also avoid disrupting sea turtle nesting areas. Describe one trade-off they must consider.
A trade-off happens when improving one goal may make another goal harder to meet.
One trade-off is that a large or rigid barrier may protect the shoreline better, but it could block or disturb sea turtle nesting areas. The team must balance erosion reduction with protecting the local ecosystem. - 10
A lab group tests an insulated cup design by measuring water temperature every 5 minutes for 30 minutes. What type of data should they collect, and how would that data help them improve the design?
They should collect quantitative temperature data over time and compare it with a control cup. The data would show how quickly heat is lost, helping them decide whether to add insulation, change materials, or improve the lid. - 11
A school wants to reduce electricity use in classrooms. Apply the first three steps of the engineering design process: define the problem, research the science, and brainstorm possible solutions.
Connect each solution to the scientific idea of energy conservation.
The problem is that classrooms use too much electricity. Research should include how lighting, heating, cooling, and electronics use energy. Possible solutions include motion-sensor lights, better insulation, efficient bulbs, smart thermostats, and student reminders to turn off devices. - 12
A team designs a flood warning system using a water-level sensor. During testing, the alarm sometimes triggers when waves splash the sensor even though the river level is safe. Identify the design problem and propose a redesign.
The design problem is that the sensor gives false alarms when short-term splashes are detected. A redesign could require the water level to stay above the danger threshold for a set time, or use a protective tube around the sensor to reduce wave splashes. - 13
A team must choose between two materials for a bridge model. Material X is stronger but more expensive. Material Y is cheaper but bends more under load. Explain how the team should make an evidence-based decision.
Use data and the project goals rather than personal preference.
The team should compare test data for strength, bending, cost, and safety against the project criteria and constraints. If the bridge must hold a heavy load, Material X may be worth the higher cost. If Material Y still meets the load requirement and stays within safe bending limits, it may be the better choice because it costs less. - 14
A group designing a compost bin finds that the inside stays too dry for decomposition to happen efficiently. Explain how understanding biology and chemistry can guide a redesign.
Biology shows that decomposer organisms need moisture, oxygen, and suitable temperature to break down organic matter. Chemistry shows that decomposition depends on reactions involving carbon-rich and nitrogen-rich materials. The team could redesign the bin to retain moisture, add ventilation, and balance green and brown compost materials. - 15
Create a brief test plan for a student-built device that removes microplastic particles from water. Include the independent variable, dependent variable, one control variable, and how success will be judged.
A fair test changes one main factor and keeps other important factors the same.
The independent variable could be the filter material. The dependent variable could be the percentage of microplastic particles removed from the water. One control variable should be the volume of water tested each time. Success could be judged by whether the device removes at least 90 percent of particles while still allowing water to flow through in a reasonable time.