Middle School Science Quiz: Set Heat Device Requirements
20 questions · exam conditions
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Set Heat Device RequirementsQuestion 1 of 20

Cold drink cooler design challenge: You are designing a cooler for an outdoor event lasting 4 hours in 30°C weather. It must keep the drinks at or below 10°C. It must hold 12 standard cans. The budget is $50. It must be portable (handles or wheels), durable for repeated use, and you can use foam, plastic, and ice/ice packs.

Which option best identifies the constraints (limits) for this design?

Keep drinks at or below 10°C for 4 hours and hold 12 cans
Use a thermometer to check the temperature every hour
Budget $50, must be portable and durable, and materials are limited to foam/plastic/ice packs
Hold 12 cans and keep them cold and refreshing
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Middle School Science Quiz

Middle School Science Quiz: Set Heat Device Requirements

Practice Set Heat Device Requirements in Middle School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Set Heat Device Requirements, giving you a quick way to practice the rules, question types, and explanations that matter most for Middle School Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Cold drink cooler design challenge: You are designing a cooler for an outdoor event lasting 4 hours in 30°C weather. It must keep the drinks at or below 10°C. It must hold 12 standard cans. The budget is $50. It must be portable (handles or wheels), durable for repeated use, and you can use foam, plastic, and ice/ice packs.

Which option best identifies the constraints (limits) for this design?

  1. Keep drinks at or below 10°C for 4 hours and hold 12 cans
  2. Use a thermometer to check the temperature every hour
  3. Budget $50, must be portable and durable, and materials are limited to foam/plastic/ice packs (correct answer)
  4. Hold 12 cans and keep them cold and refreshing
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≤10°C temperature, work for 4 hours duration, hold 12 cans capacity), which are measurable targets that testing will verify (thermometer measures if temp ≤10°C met, timer measures if 4 hour duration met, count cans to verify 12 fit); and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $50 budget, must be portable with handles/wheels, must be durable for repeated use, materials limited to foam/plastic/ice packs), which bound the solution space preventing unlimited resources or unrealistic designs. For this cold drink cooler: The criteria (performance goals) are: (1) maintain ≤10°C (temperature criterion: drinks must stay cold and refreshing in hot weather, 10°C is cool enough for enjoyment, testable with thermometer at end of 4 hours), (2) duration of 4 hours (time criterion: length of outdoor event, must keep cold this long, testable with timer), and (3) capacity 12 cans (volume criterion: must hold enough drinks for event, testable by counting cans that fit). The constraints (limitations) are: (1) cost under $50 (budget constraint: event organizer can afford, eliminates expensive commercial coolers perhaps, testable by adding component costs), (2) portable with handles or wheels (mobility constraint: must move from storage to event location, testable by lifting/rolling), (3) durable for repeated use (longevity constraint: not single-use, must last multiple events, testable through repeated use cycles), and (4) materials limited to foam, plastic, ice packs (resource constraint: can't use exotic materials, limits design choices). Choice C is correct because it accurately identifies constraints as limitations (budget $50, portability requirement, durability need, and material restrictions—boundaries to work within). Choice A lists criteria (temperature and capacity goals), not constraints; Choice B describes a testing method, not a constraint or criterion; Choice D mixes a criterion (hold 12 cans) with vague language ("cold and refreshing") and doesn't identify constraints. Establishing clear design requirements is the essential first step in engineering design process: constraints define the boundaries within which you must work (can't exceed $50, must be portable, must use available materials), while criteria define what success looks like within those boundaries (keep drinks ≤10°C for 4 hours while holding 12 cans). The distinction is clear: criteria describe what the device must DO (maintain temp, hold volume, work for time), while constraints describe what you must work WITHIN (cost limit, portability requirement, material limit)—criteria are achievements, constraints are boundaries.

Question 2

Hot lunch container design challenge: Keep 500 mL of soup at or above 60°C for 5 hours. Constraints: cost under $20, height ≤ 15 cm, safe for students (no burn risk from the outside), materials limited to plastic/foam/metal.

Which option is an example of a constraint rather than a criterion?

  1. The soup must be at least 60°C at 12:00 PM.
  2. The container must hold 500 mL of soup.
  3. The container must keep the soup hot for 5 hours.
  4. The container must cost less than $20. (correct answer)
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≥60°C temperature, work for 5 hours duration, hold 500 mL capacity, ensure safe exterior), which are measurable targets that testing will verify; and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $20 budget, height ≤15 cm for backpack fit, materials limited to plastic/foam/metal). The distinction is fundamental: criteria describe WHAT the design must achieve (performance outcomes), while constraints describe LIMITS on how you achieve it (boundaries and restrictions). For this hot lunch container: Criteria (performance goals) include "soup at least 60°C at 12:00 PM" (temperature maintenance goal), "keep soup hot for 5 hours" (duration goal), and "hold 500 mL of soup" (capacity goal)—these all describe what the container must DO. Constraints (limitations) include "cost less than $20" (budget boundary), "height ≤15 cm" (size restriction for backpack fit), "safe exterior/no burn risk" (safety limitation), and "materials limited to plastic/foam/metal" (resource restriction)—these all describe limits WITHIN WHICH the design must work. Choice D is correct because "cost less than $20" is a constraint rather than a criterion—it's a limitation (budget boundary) that restricts design options, not a performance goal the design must achieve. Choice A describes a criterion (temperature performance goal: maintain ≥60°C); Choice B describes a criterion (capacity performance goal: hold 500 mL); Choice C describes a criterion (duration performance goal: work for 5 hours). The cost constraint affects design decisions: limits material choices (can't use expensive vacuum-insulated steel), restricts complexity (can't add electronic heating elements), requires economical solutions (foam insulation instead of aerogel), but doesn't define what the container must accomplish—that's what criteria do. Understanding this distinction guides the design process: first establish what success looks like (criteria: keep soup ≥60°C for 5 hours), then identify boundaries to work within (constraints: only $20 budget, specific size limits), and finally create designs that meet all criteria while respecting all constraints (achieve temperature goals using affordable materials within size limits).

Question 3

A student is designing a cooler for an outdoor event. It will be used for 4 hours outside in 30∘C30^\circ\text{C} weather. It must keep the drinks at ≤10∘C\le 10^\circ\text{C}, hold 12 standard cans, and be safe to use. Constraints include a $50 budget, portability (handles or wheels), durability for repeated use, and available materials are foam, plastic, and ice/ice packs.

Which statement best describes the difference between criteria and constraints in this challenge?

  1. Criteria are the limits (like budget and size), while constraints are the goals (like temperature and time).
  2. Criteria describe what the cooler must accomplish (like ≤10∘C\le 10^\circ\text{C} for 4 hours and holding 12 cans), while constraints describe limits (like $50 budget and available materials). (correct answer)
  3. Criteria are optional features to make it look better, while constraints are the required features.
  4. Criteria and constraints mean the same thing as long as they include numbers.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: keep ≤10°C, hold 12 cans, be safe), measurable and testable; and (2) constraints—the limitations (budget $50, portability, durability, materials foam/plastic/ice packs), bounding the design; both ensure realistic, verifiable solutions. For this cooler, criteria are temperature ≤10°C for 4 hours and holding 12 cans, while constraints are $50 budget and available materials; the difference is criteria define what to achieve (goals), constraints define limits to work within, essential for distinguishing performance from boundaries. Choice B is correct because it properly distinguishes criteria from constraints (goals like temperature and capacity vs limits like budget and materials). Choice A reverses the definitions; choice C treats criteria as optional aesthetics; choice D says they are the same. Establishing clear design requirements is the essential first step in engineering design process: set measurable criteria and realistic constraints to guide, test, and improve designs systematically, with good examples being specific and testable.

Question 4

Design challenge (Ice cream transport): Hold 1 L1\,\text{L} of ice cream and keep it at or below −5∘C-5^\circ\text{C} for 30 minutes. Constraints: cost under $15, portable, no leaks, food-safe materials.

Which set of requirements includes all the key measurable criteria needed to judge success?

  1. Portable; looks nice; keeps ice cream cold
  2. Cost under $15; food-safe; easy to carry
  3. Keep temperature ≤−5∘C\le -5^\circ\text{C} for 30 minutes; hold 1 L1\,\text{L}; does not leak (safety/quality requirement) (correct answer)
  4. Use foam; use plastic; use a lid that snaps shut
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Complete design requirements must include all key measurable criteria that define success—missing any critical criterion means you cannot fully evaluate if the design succeeds (like trying to judge a race without knowing the finish line). For ice cream transport, the key criteria are: (1) temperature maintenance ≤-5°C (primary function: keep ice cream frozen), (2) duration of 30 minutes (time requirement: store to home), (3) capacity of 1 L (volume requirement: hold the ice cream), and (4) no leaking (quality/safety requirement: prevent mess and product loss). These are all measurable: thermometer verifies ≤-5°C, timer confirms 30 minutes, measuring cup checks 1 L capacity, and visual inspection confirms no leaks. Choice C is correct because it includes all the key measurable criteria needed to judge success (keep temperature ≤-5°C for 30 minutes—combines temperature and time criteria; hold 1 L—capacity criterion; does not leak—safety/quality criterion; all are specific, measurable, and together fully define successful performance). Choice A lists vague unmeasurable terms ("portable" and "looks nice" are subjective, "keeps ice cream cold" lacks specific temperature), Choice B lists only constraints not criteria (cost limit, food-safety, and portability are all limitations not performance goals), and Choice D lists design specifications not criteria (specifying exact materials and lid type constrains design choices but doesn't define what to achieve). Complete criteria enable comprehensive evaluation: test each criterion systematically (temperature after 30 min: -7°C ✓, volume held: 1 L ✓, leaking observed: none ✓), confirm all criteria met for success (missing any = failure), distinguish from partial success (3 of 4 criteria met still means design needs improvement), and guide design improvements (if temperature was -3°C, focus on better insulation).

Question 5

A student is designing a hot lunch container (like a thermos) to keep soup hot from 7:00 AM until 12:00 PM (5 hours). The container must hold 500 mL of soup and the soup must still be at least 60∘C60^\circ\text{C} at noon. It must cost under $20, fit in a backpack (maximum 15 cm tall), and be safe for students (the outside should not burn hands). Plastic, foam, and metal are available materials.

Which option lists ONLY the criteria (performance goals) for this design?

  1. Cost under $20, maximum height 15 cm, and made only from plastic/foam/metal
  2. Hold 500 mL of soup and keep the soup at ≥60∘C\ge 60^\circ\text{C} for 5 hours (correct answer)
  3. Fit in a backpack and have a cool-to-the-touch exterior
  4. Use foam insulation, add a metal lining, and include a handle
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≥60°C temperature, work for 5 hours duration, hold 500 mL capacity, ensure safety with no burn risk from exterior), which are measurable targets that testing will verify (thermometer measures if temp ≥60°C met, timer measures if 5 hour duration met, pass/fail clear from measurements); and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $20 budget, size fits in backpack max 15 cm tall, materials limited to available foam/plastic/metal), which bound the solution space preventing unlimited resources or unrealistic designs; both are essential: criteria without constraints could be met with expensive exotic materials (not realistic), constraints without criteria leave unclear what to accomplish (insulated box but no temp target?—how to judge success?). For this hot lunch container, the criteria (performance goals) are: (1) maintain ≥60°C (temperature criterion: soup must stay at safe eating temperature, 60°C is minimum for hot food safety, testable with thermometer at end of 5 hours), (2) duration of 5 hours (time criterion: from 7 AM packing to noon eating, must keep hot this long, testable with timer), (3) capacity 500 mL (volume criterion: must hold a meal-sized portion, testable with measuring cup), and (4) safety (no burn hazard: exterior cool enough to touch even with hot soup inside, testable by touching exterior); the constraints (limitations) are: (1) cost under $20 (budget constraint: student/family can afford, eliminates expensive vacuum thermoses perhaps, testable by adding component costs), (2) size max 15 cm tall (dimensions constraint: to fit in backpack with books, testable with ruler), and (3) materials available to foam, plastic, metal (resource constraint: can't use exotic materials not accessible, limits design choices); the distinction is clear: criteria describe what the device must DO (maintain temp, hold volume, work for time, ensure safety), while constraints describe what you must work WITHIN (cost limit, size limit, material limit)—criteria are achievements, constraints are boundaries. Choice B is correct because it correctly identifies criteria as measurable performance goals (hold 500 mL capacity, keep soup at ≥60°C for 5 hours duration) and lists only those without including any constraints. Choice A confuses criteria and constraints by listing cost, size, and materials which are limitations, not performance goals; choice C mixes a constraint (fit in backpack, i.e., size) with a criterion (cool exterior for safety); choice D lists specific design solutions (use foam, metal lining, handle) which are ideas for how to meet requirements, not the requirements themselves. Establishing clear design requirements is the essential first step in engineering design process: (1) understand the problem (what needs to be kept hot? for how long? under what conditions?), (2) set criteria defining success (specific measurable goals: maintain ≥60°C, work for 5 hours, hold 500 mL—know exactly what 'success' means), (3) establish constraints defining boundaries (realistic limits: budget $20, size 15 cm, available materials—work within practical boundaries), (4) make criteria testable (quantitative values allow objective pass/fail: thermometer reads 62°C at 5 hours = pass, reads 58°C = fail—no ambiguity), and (5) prioritize if needed (if cost and performance conflict, which matters more? for student lunch, maybe prioritize low cost); examples of good vs poor requirements: GOOD: 'maintain internal temperature ≥60°C for minimum 5 hours when external temperature is 20°C, tested by thermocouple at 1, 3, and 5 hour intervals' (specific, measurable, testable, clear conditions); POOR: 'keep food hot' (how hot? for how long? in what conditions? can't test objectively, too vague); the specificity helps guide design decisions, evaluate designs objectively, compare alternatives, and improve systematically—all starting from clear measurable requirements.

Question 6

Design challenge: Cold drink cooler for an outdoor event. Goal: keep drinks cold for 4 hours when the outside air is 30∘C30^\circ\text{C}. Criteria: keep drinks at ≤10∘C\le 10^\circ\text{C} for 4 hours and hold 12 standard cans. Constraints: budget $50, portable (wheels or handles), durable for repeated use. Available materials: foam, plastic, ice/ice packs.

Which is the best way to test whether the cooler meets the temperature criterion?

  1. Ask people if the drinks feel cold.
  2. Measure the drink temperature with a thermometer at the start and again after 4 hours; it passes if it is ≤10∘C\le 10^\circ\text{C} at 4 hours. (correct answer)
  3. Check whether the cooler cost less than $50.
  4. Count how many handles the cooler has.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (keep drinks ≤10°C for 4 hours, hold 12 cans), measurable and testable; and (2) constraints—the limitations (budget $50, portable, durable, materials like foam/plastic/ice). Both are essential: criteria define success, constraints bound realism. For making criteria testable: Changing vague 'keep drinks cold' to specific 'maintain ≤10°C for 4 hours' makes it testable: (1) measure starting temperature, (2) wait 4 hours, (3) measure final temperature with thermometer, (4) compare to criterion (≤10°C = pass). Specific measurable criteria enable objective evaluation: everyone knows exactly what to achieve, testing is unambiguous (thermometer gives number), and improvement targets are clear. Choice B is correct because it appropriately makes requirements testable with specific measurable values (measure temperature at start and after 4 hours, pass if ≤10°C). Choice A provides vague unmeasurable criteria like 'feel cold' (subjective, not objective); Choice C checks a constraint (cost) not the temperature criterion; Choice D is irrelevant (handles not related to temperature). Establishing clear design requirements is the essential first step: set testable criteria for objective verification. The specificity helps: guide design, evaluate objectively, compare alternatives, improve systematically.

Question 7

Design challenge: Hot lunch container. Goal: keep soup hot from 7:00 AM until noon (5 hours). Criteria: soup must be ≥60∘C\ge 60^\circ\text{C} at noon; must hold 500 mL; exterior must be safe to touch. Constraints: under $20; max height 15 cm; materials limited to plastic, foam, metal.

Which option correctly matches each item as a criterion or a constraint?

  1. Cost under $20 = criterion; keep soup $\ge 60^\circ\text{C}$ = constraint.
  2. Hold 500 mL = constraint; materials (plastic/foam/metal) = criterion.
  3. Keep soup ≥60∘C\ge 60^\circ\text{C} at noon = criterion; max height 15 cm = constraint. (correct answer)
  4. Exterior safe to touch = constraint; cost under $20 = criterion.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria (≥60°C at noon, hold 500 mL, safe exterior); (2) constraints (under $20, max 15 cm, materials plastic/foam/metal). Both are essential: criteria define success, constraints bound options. The distinction is clear: criteria are performance goals (temp, capacity), constraints limits (cost, size). For hot lunch container: Correct matching identifies temp as criterion (goal), height as constraint (limit). Choice C is correct because it properly distinguishes criteria from constraints (≥60°C at noon as criterion, max height 15 cm as constraint). Choice A confuses by swapping cost and temp; Choice B swaps capacity and materials; Choice D swaps safe touch and cost. Establishing clear design requirements is essential: correctly distinguish for effective design. Requirements cascade: criteria targets, constraints boundaries, correct matching ensures clarity.

Question 8

Design challenge: Cold drink cooler for an outdoor event (4 hours, 30∘C30^\circ\text{C} outside). Criteria: drinks must stay ≤10∘C\le 10^\circ\text{C} for 4 hours; must hold 12 standard cans; must be safe (no sharp edges, non-toxic materials). Constraints: budget $50; portable (wheels or handles); durable for repeated use; materials available include foam, plastic, ice/ice packs.

Which requirement is most critical to prioritize if the goal is "cold and refreshing drinks" at the end of the event?

  1. The cooler must have a bright color.
  2. The cooler must keep drinks at ≤10∘C\le 10^\circ\text{C} after 4 hours. (correct answer)
  3. The cooler must be made of plastic only.
  4. The cooler must cost exactly $50.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria (≤10°C for 4 hours, hold 12 cans, safe); (2) constraints ($50 budget, portable, durable, materials foam/plastic/ice). Both are essential, but prioritize core goals like temperature for 'cold drinks'. The distinction is clear: criteria describe what must be achieved (cold drinks), constraints limits (budget). Specific measurable criteria enable objective evaluation, and prioritization ensures key goals like temperature are met first. Choice B is correct because it correctly identifies criteria as measurable performance goals (keep ≤10°C after 4 hours, critical for 'cold and refreshing drinks'). Choice A lists irrelevant criteria (bright color); Choice C confuses with materials constraint; Choice D distorts cost constraint to 'exactly $50'. Establishing clear design requirements includes prioritizing: for cold drinks, temperature criterion is most critical. The specificity helps compare and improve designs focused on priorities.

Question 9

Design challenge: Laboratory sample storage for transport. Goal: keep biological samples at 4∘C4^\circ\text{C} for 8 hours. Criteria: temperature must stay from 2∘C2^\circ\text{C} to 6∘C6^\circ\text{C} for 8 hours; hold 200 mL; temperature monitoring required; shock-resistant. Constraint: total cost \le \100.

Which proposed requirement is not appropriate because it is not measurable?

  1. Temperature must stay between 2∘C2^\circ\text{C} and 6∘C6^\circ\text{C} for 8 hours.
  2. The device should be the safest possible. (correct answer)
  3. The device must hold 200 mL of samples.
  4. Total cost must be \le \100.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria (2-6°C for 8 hours, hold 200 mL, monitoring, shock-resistant); (2) constraints (≤$100 cost). Both are essential, but criteria must be measurable for testability—vague terms like 'safest possible' are not. For making criteria testable: Specific temp range is measurable with thermometer, unlike subjective 'safest'. Specific measurable criteria enable objective evaluation and clear pass/fail. Choice B is correct because it identifies the non-measurable requirement ('safest possible' is subjective, not testable). Choice A is measurable (temp range); Choice C is measurable (volume); Choice D is measurable but a constraint. Establishing clear design requirements requires measurability for objective verification. Examples: GOOD: specific metrics; POOR: vague subjective terms.

Question 10

Design challenge: Transport ice cream from the store to home in 30 minutes without melting. Criteria: keep ≤−5∘C\le -5^\circ\text{C} for 30 minutes; hold 1 liter. Constraints: under $15, portable, doesn't leak, food-grade materials.

Which requirement is a constraint, not a criterion?

  1. Keep the ice cream at ≤−5∘C\le -5^\circ\text{C} for 30 minutes.
  2. Hold 1 liter of ice cream.
  3. Cost must be under $15. (correct answer)
  4. Prevent melting during the trip.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria (≤-5°C for 30 minutes, hold 1 liter); (2) constraints (under $15, portable, no leak, food-grade). Both are essential: criteria define what to do, constraints limit how. The distinction is clear: criteria are achievements (temp, capacity), constraints are boundaries (cost, portability). For ice cream transport: Criteria focus on performance (keep frozen, hold volume), constraints on limits (budget, materials). Choice C is correct because it accurately identifies constraints as limitations (cost under $15 bounds the design). Choice A confuses criteria and constraints: lists temperature as constraint when it's a criterion; Choice B lists capacity as constraint; Choice D is a vague criterion ('prevent melting'). Establishing clear design requirements is the first step: distinguish criteria from constraints for bounded goals. Requirements cascade: criteria set targets, constraints boundaries, testing verifies both.

Question 11

A student is designing a container to transport ice cream from a store to home in 30 minutes. The container must keep the ice cream at ≤−5∘C\le -5^\circ\text{C} and hold 1 liter. Constraints: total cost under $15, portable (easy to carry), does not leak, and all materials must be food-grade.

Which requirement is not written as a measurable, testable criterion?

  1. The ice cream stays at ≤−5∘C\le -5^\circ\text{C} for 30 minutes.
  2. The container holds 1 liter of ice cream.
  3. The container keeps the ice cream really cold. (correct answer)
  4. The container does not leak during a 30-minute trip.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (maintain ≤-5°C for 30 minutes, hold 1 liter, no leaking), measurable and testable; and (2) constraints—limitations (under $15, portable, food-grade materials). For ice cream transport, good criteria are specific like ≤-5°C (testable with thermometer) or holds 1 liter (measurable with cup), while vague ones like 'really cold' are not testable (what temperature? subjective). Choice C is correct because it provides vague unmeasurable criteria like 'keep really cold' without specific temperature value (can't test objectively). Choice A is measurable (≤-5°C, thermometer test); choice B is measurable (1 liter capacity); choice D is testable (check for leaks after 30 minutes). Establishing clear design requirements is the essential first step in engineering design process: make criteria testable with specific values to enable objective evaluation and systematic improvement.

Question 12

A student is building a hot lunch container to keep 500 mL of soup hot from 7:00 AM to 12:00 PM. The soup must be ≥60∘C\ge 60^\circ\text{C} at noon. Constraints: under $20, maximum height 15 cm, safe exterior (no burn risk), and only plastic/foam/metal available.

Which requirement is a constraint rather than a criterion?

  1. Soup temperature at noon is at least 60∘C60^\circ\text{C}.
  2. The container holds 500 mL of soup.
  3. The container is no taller than 15 cm. (correct answer)
  4. The container keeps the soup hot for 5 hours.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—goals like ≥60°C at noon, hold 500 mL; (2) constraints—limits like under $20, max 15 cm, safe exterior, materials. Here, constraints limit design options (e.g., height 15 cm bounds size), while criteria are achievements (e.g., temperature is a goal, not limit). Choice C is correct because it accurately identifies constraints as limitations (no taller than 15 cm is a size boundary, not a performance goal). Choice A is a criterion (temperature goal); choice B is a criterion (capacity); choice D is a vague criterion (keep hot for 5 hours). Establishing clear design requirements is the essential first step in engineering design process: distinguish goals from limits to create realistic, testable designs.

Question 13

A lab transport device must keep samples between 2∘C2^\circ\text{C} and 6∘C6^\circ\text{C} for 8 hours and hold 200 mL. Constraints: $100 budget, insulated, shock-resistant, and it must include temperature monitoring.

Which revised requirement is the BEST example of making a vague idea into a measurable criterion?

  1. The container should keep the samples cold.
  2. The container should be high quality.
  3. The container must keep the samples between 2∘C2^\circ\text{C} and 6∘C6^\circ\text{C} for 8 hours. (correct answer)
  4. The container should use the best insulating material.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—specific goals like 2-6°C for 8 hours, hold 200 mL; (2) constraints—$100 budget, insulated. The best revision turns vague ideas (e.g., 'cold') into measurable ones with numbers and tests (e.g., temperature range over time). Choice C is correct because it changes vague 'keep cold' to specific 'between 2-6°C for 8 hours' (measurable with thermometer). Choice A remains vague ('cold'); choice B is subjective ('high quality'); choice D is vague ('best material'). Establishing clear design requirements is the essential first step in engineering design process: specific criteria enable objective verification and improvement.

Question 14

Design challenge (Ice cream transport): You need a portable container to transport 1 L1\,\text{L} of ice cream from the store to home in 30 minutes. The ice cream must stay frozen at or below −5∘C-5^\circ\text{C}. The container must cost under $15, be easy to carry, not leak, and use food-safe materials.

Which option lists only the constraints (limits you must work within)?

  1. Keep ice cream ≤−5∘C\le -5^\circ\text{C}; transport time 30 minutes; hold 1 L1\,\text{L}
  2. Cost under $15; portable/easy to carry; does not leak; materials must be food-safe (correct answer)
  3. Keep ice cream frozen; cost under $15; hold 1 L1\,\text{L}
  4. Keep ice cream ≤−5∘C\le -5^\circ\text{C}; does not leak; materials must be food-safe
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≤-5°C temperature, work for 30 minutes duration, hold 1 L capacity, prevent leaking), which are measurable targets that testing will verify (thermometer measures if temp ≤-5°C met, timer measures if 30 minute duration met, pass/fail clear from measurements); and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $15 budget, must be portable/carriable, materials must be food-safe), which bound the solution space preventing unlimited resources or unrealistic designs. For this ice cream transport container: The criteria (performance goals) are: (1) maintain ≤-5°C (temperature criterion: ice cream must stay frozen solid, -5°C ensures frozen state, testable with thermometer after 30 minutes), (2) duration of 30 minutes (time criterion: from store to home transport time, testable with timer), (3) capacity 1 L (volume criterion: must hold standard ice cream container size, testable with measuring), and (4) no leaking (functional criterion: melted ice cream must not escape, testable by inspection). The constraints (limitations) are: (1) cost under $15 (budget constraint: affordable for regular use, testable by adding component costs), (2) portable/easy to carry (usability constraint: must transport by hand/car, testable by carrying), and (3) food-safe materials (safety constraint: materials must not contaminate food, verified by material specifications). Choice B is correct because it accurately identifies constraints as limitations (cost under $15 budget limit, portable/easy to carry usability requirement, no leaking functional requirement, food-safe materials safety requirement—all boundaries to work within). Choice A lists only criteria (temperature goal, time duration, capacity—all performance goals), Choice C mixes criteria (keep frozen) with constraints (cost limit), and Choice D mixes criteria (temperature goal, no leaking) with constraints (food-safe materials). Establishing clear design requirements is the essential first step in engineering design process: understand the problem (transport ice cream home without melting), set criteria defining success (specific measurable goals: maintain ≤-5°C, work for 30 minutes, hold 1 L—know exactly what "success" means), establish constraints defining boundaries (realistic limits: budget $15, must be carriable, food-safe materials—work within practical boundaries), make criteria testable (quantitative values allow objective pass/fail: thermometer reads -6°C at 30 minutes = pass, reads -3°C = fail—no ambiguity), and ensure all constraints are met (total cost $14 = within budget, weight 2 kg = carriable, materials FDA-approved = food-safe).

Question 15

Design challenge (Hot lunch container): Keep 500 mL500\,\text{mL} of soup at ≥60∘C\ge 60^\circ\text{C} from 7:00 AM until noon (5 hours). Constraints: cost under $20, height ≤15 cm\le 15\,\text{cm}, safe exterior (no burn risk), and materials limited to plastic/foam/metal.

A student writes this requirement: "The soup should be warm at lunchtime."

Which revision makes this requirement a measurable criterion?

  1. The container should look nice and be easy to open.
  2. The soup must stay ≥60∘C\ge 60^\circ\text{C} for at least 5 hours, measured with a thermometer. (correct answer)
  3. The container must be made of foam because foam is a good insulator.
  4. The soup should stay warm for a long time.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements must be specific and measurable to enable objective testing—vague requirements like "warm" or "long time" cannot be tested because there's no clear threshold for success (one person might consider 40°C "warm" while another expects 70°C, making evaluation subjective and inconsistent). For making criteria testable: Changing vague "keep soup warm at lunchtime" to specific "maintain ≥60°C for 5 hours" makes it testable: (1) measure starting temperature when soup added (ensure starts hot, >70°C ideally), (2) seal container, (3) wait 5 hours (or test at intervals: 1 hr, 3 hr, 5 hr), (4) measure final temperature with thermometer (read °C value), (5) compare to criterion (if ≥60°C then criterion MET ✓, if <60°C then NOT MET ✗), and (6) document results (60°C exactly is pass, 59°C is fail—clear threshold). Choice B is correct because it makes the requirement a measurable criterion (the soup must stay ≥60°C for at least 5 hours, measured with a thermometer—specific temperature threshold, specific time duration, specific measurement method, objective pass/fail determination). Choice A describes preferences not performance requirements (appearance and ease of opening don't relate to thermal performance), Choice C specifies a material which is a design decision not a criterion (foam might be good choice but criterion should state what to achieve, not how), and Choice D remains vague and untestable ("warm" has no specific temperature, "long time" has no specific duration—cannot objectively evaluate). Establishing clear measurable criteria enables: objective evaluation (everyone knows exactly what to achieve: ≥60°C, not subjective "warm enough"), clear testing procedures (use thermometer at 5 hours, compare to 60°C threshold), design comparison (Design A achieves 65°C, Design B achieves 58°C—A succeeds, B fails), and targeted improvement (if achieved 55°C, know need 5°C improvement in thermal performance).

Question 16

Design challenge (Ice cream transport): Hold 1 L1\,\text{L} of ice cream and keep it at or below −5∘C-5^\circ\text{C} for 30 minutes. Constraints include cost under $15, portable, no leaks, and food-safe materials.

Which requirement below is a constraint, not a criterion?

  1. The container must keep the ice cream ≤−5∘C\le -5^\circ\text{C}.
  2. The container must hold 1 L1\,\text{L} of ice cream.
  3. The container must cost less than $15. (correct answer)
  4. The container must work for 30 minutes.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: keep ice cream ≤-5°C, hold 1 L volume, work for 30 minutes), which are measurable targets that testing will verify; and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $15 budget, must be portable, no leaks allowed, food-safe materials required), which bound the solution space. The distinction is fundamental: criteria are what you must achieve (performance goals), constraints are what you must work within (limitations/boundaries). For this ice cream transport design: Criteria include maintain ≤-5°C (temperature goal), hold 1 L (capacity goal), and work for 30 minutes (duration goal)—all measurable performance targets. Constraints include cost under $15 (budget limitation), portable design (usability limitation), leak-proof (safety/quality limitation), and food-safe materials (regulatory limitation)—all boundaries within which the solution must fit. Choice C is correct because it identifies a constraint, not a criterion (the container must cost less than $15 is a budget constraint—a limitation on resources, not a performance goal to achieve). Choices A, B, and D all describe criteria: Choice A is temperature maintenance criterion (keep ≤-5°C), Choice B is capacity criterion (hold 1 L volume), and Choice D is duration criterion (work for 30 minutes)—all are performance goals the design must achieve. Understanding this distinction is crucial for design: criteria tell you what success looks like (frozen ice cream after 30 minutes), constraints tell you the boundaries of acceptable solutions (can't spend $50 on exotic vacuum container), both must be satisfied (achieve all criteria while respecting all constraints), and testing verifies criteria while procurement/design confirms constraints.

Question 17

Design challenge (Hot lunch container): Keep 500 mL500\,\text{mL} of soup at ≥60∘C\ge 60^\circ\text{C} for 5 hours. Constraints: cost under $20, height ≤15 cm\le 15\,\text{cm}, safe exterior (no burn risk), and materials limited to plastic/foam/metal.

Which item below correctly matches a criterion with the tool you would use to test it?

  1. Cost under $20 — thermometer
  2. Height ≤15 cm\le 15\,\text{cm} — stopwatch
  3. Soup stays ≥60∘C\ge 60^\circ\text{C} at noon — thermometer (correct answer)
  4. Use plastic/foam/metal — measuring cup
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). To test requirements, you must match each requirement with appropriate measurement tools—criteria need tools that measure performance (thermometer for temperature, timer for duration, scale for mass), while constraints need tools that verify limits (ruler for dimensions, calculator for cost, material specifications for safety). For this hot lunch container: Criteria include maintaining ≥60°C (needs thermometer to measure temperature), working for 5 hours (needs timer/clock to measure duration), holding 500 mL (needs measuring cup to verify volume), and safe exterior (needs touch test or surface thermometer). Constraints include cost under $20 (needs cost calculation adding components), height ≤15 cm (needs ruler to measure dimension), and specified materials (needs visual inspection or material list). Choice C is correct because it correctly matches a criterion with the tool to test it (soup stays ≥60°C at noon is a temperature criterion—thermometer measures temperature to verify if ≥60°C threshold is met after 5 hours). Choice A incorrectly matches constraint with wrong tool (cost under $20 is a constraint not criterion, and thermometer doesn't measure cost—need calculator/receipts), Choice B matches constraint with wrong tool (height ≤15 cm is a constraint not criterion, and stopwatch doesn't measure height—need ruler), and Choice D matches constraint with wrong tool (material limitation is a constraint not criterion, and measuring cup doesn't verify materials—need visual inspection). Proper testing requires: identifying what type of requirement it is (criterion = performance goal, constraint = limitation), selecting appropriate measurement tool (temperature → thermometer, dimension → ruler, cost → calculator), establishing test procedure (when/how to measure), and recording results to compare against requirement (62°C measured > 60°C required = pass).

Question 18

Cold drink cooler design challenge: Keep 12 cans at or below 10°C for 4 hours in 30°C weather. Constraints: budget $50, portable (handles or wheels), durable, materials limited to foam/plastic/ice packs.

A team proposes adding this requirement: "The cooler must weigh less than 2 kg."

How should this new requirement be classified?

  1. It is a constraint because it limits the design's weight for portability. (correct answer)
  2. It is a criterion because it describes the temperature the drinks must reach.
  3. It is a criterion because it describes how long the cooler must work.
  4. It is neither; weight can't be measured.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≤10°C temperature, work for 4 hours duration, hold 12 cans capacity), which are measurable targets that testing will verify; and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: 50budget,mustbeportablewithhandles/wheels,mustbedurableforrepeateduse,materialslimitedtofoam/plastic/icepacks).Whenaddingnewrequirements,youmustdeterminewhethertheydescribewhatthedesignmustachieve(criterion)orwhatlimitsthedesignmustworkwithin(constraint).Theproposedrequirement"mustweighlessthan2kg"setsaweightlimitthataffectsdesignchoices:itrestrictsmaterialselection(heavymaterialseliminated),limitsinsulationthickness(moreinsulation=moreweight),affectsice/coolingcapacity(iceaddsweight),andensuresportability(lighter=easiertocarry)—thisisclearlyalimitationonHOWthedesigncanbebuilt,notWHATitmustaccomplish.ChoiceAiscorrectbecauseweightlimitisaconstraintthatlimitsthedesign′sweightforportability—it′saboundarycondition(maximum2kg)thatrestrictsdesignoptionstoensurethecoolerremainsportableandpracticaltocarry.ChoiceBincorrectlycallsitacriterionabouttemperature,but2kgisweightnottemperature;ChoiceCincorrectlycallsitacriterionaboutduration,butweightdoesn′tdescribehowlongthecoolerworks;ChoiceDincorrectlyclaimsweightcan′tbemeasured,whenscaleseasilymeasureweightinkg.Weightconstraintsarecommoninportabledesigns:theyensureusability(tooheavy=hardtocarry),affectmaterialchoices(aluminumvssteel,foamthickness),mayconflictwithperformance(moreinsulation=bettercoolingbutheavier),andrequireoptimization(achievecoolinggoalswithinweightlimit).Thedistinctionmattersfordesigndecisions:criteriatellyouwhattoachieve(keepdrinks≤10°Cfor4hours),constraintstellyoulimitstoworkwithin(weigh≤2kg,cost≤50 budget, must be portable with handles/wheels, must be durable for repeated use, materials limited to foam/plastic/ice packs). When adding new requirements, you must determine whether they describe what the design must achieve (criterion) or what limits the design must work within (constraint). The proposed requirement "must weigh less than 2 kg" sets a weight limit that affects design choices: it restricts material selection (heavy materials eliminated), limits insulation thickness (more insulation = more weight), affects ice/cooling capacity (ice adds weight), and ensures portability (lighter = easier to carry)—this is clearly a limitation on HOW the design can be built, not WHAT it must accomplish. Choice A is correct because weight limit is a constraint that limits the design's weight for portability—it's a boundary condition (maximum 2 kg) that restricts design options to ensure the cooler remains portable and practical to carry. Choice B incorrectly calls it a criterion about temperature, but 2 kg is weight not temperature; Choice C incorrectly calls it a criterion about duration, but weight doesn't describe how long the cooler works; Choice D incorrectly claims weight can't be measured, when scales easily measure weight in kg. Weight constraints are common in portable designs: they ensure usability (too heavy = hard to carry), affect material choices (aluminum vs steel, foam thickness), may conflict with performance (more insulation = better cooling but heavier), and require optimization (achieve cooling goals within weight limit). The distinction matters for design decisions: criteria tell you what to achieve (keep drinks ≤10°C for 4 hours), constraints tell you limits to work within (weigh ≤2 kg, cost ≤50), and successful design meets all criteria while respecting all constraints (achieve temperature control using lightweight, affordable materials). Adding this weight constraint would require designers to carefully balance insulation effectiveness against weight, possibly using lightweight foam insulation, minimizing structural materials, and optimizing ice quantity to stay under 2 kg while still meeting the ≤10°C for 4 hours criterion.

Question 19

Laboratory sample storage design challenge: Keep samples between 2°C and 6°C for 8 hours, hold 200 mL, budget $100, insulated, temperature monitoring, shock-resistant.

Which requirement below is NOT measurable and testable as written (and should be rewritten with numbers or a clear test)?

  1. The container must keep samples between 2°C and 6°C for 8 hours.
  2. The container must hold 200 mL of samples.
  3. The container should look professional and high-tech. (correct answer)
  4. The total cost of materials must be $100 or less.
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements must be measurable and testable to enable objective evaluation: specific numbers allow clear pass/fail determination (2°C to 6°C range—thermometer reads 5°C = pass, reads 7°C = fail), defined quantities enable verification (200 mL capacity—measure with graduated cylinder), time durations allow testing (8 hours—use timer to verify), and cost limits are checkable (≤$100—add up receipts). Vague requirements cause problems: subjective terms like "good," "professional," or "high-tech" mean different things to different people, no clear test exists (how do you measure "professional"?), design decisions lack guidance (what makes something "high-tech"?), and success evaluation becomes opinion-based rather than fact-based. For this laboratory sample storage design, most requirements are properly measurable: "keep samples between 2°C and 6°C for 8 hours" (measure temperature over time), "hold 200 mL of samples" (measure volume), "cost 100orless"(addupexpenses),"shock−resistant"(couldbemademeasurablewithdroptestspecifications),and"temperaturemonitoring"(verifymonitoringequipmentincluded).ChoiceCiscorrectbecause"lookprofessionalandhigh−tech"isNOTmeasurableandtestableaswritten—it′sentirelysubjectivewithnocleartest:whatdefines"professional"?(differentpeoplehavedifferentopinions),howdoyoumeasure"high−tech"?(chromefinish?LEDdisplays?digitalreadouts?),andthere′snoobjectivepass/failcriterion(onepersonsaysitlooksprofessional,anotherdisagrees—who′sright?).ChoiceAismeasurable(usethermometertoverify2−6°Crangemaintainedfor8hours);ChoiceBismeasurable(usegraduatedcylindertoverify200mLcapacity);ChoiceDismeasurable(addreceiptstoverify≤100 or less" (add up expenses), "shock-resistant" (could be made measurable with drop test specifications), and "temperature monitoring" (verify monitoring equipment included). Choice C is correct because "look professional and high-tech" is NOT measurable and testable as written—it's entirely subjective with no clear test: what defines "professional"? (different people have different opinions), how do you measure "high-tech"? (chrome finish? LED displays? digital readouts?), and there's no objective pass/fail criterion (one person says it looks professional, another disagrees—who's right?). Choice A is measurable (use thermometer to verify 2-6°C range maintained for 8 hours); Choice B is measurable (use graduated cylinder to verify 200 mL capacity); Choice D is measurable (add receipts to verify ≤100 total cost). To make Choice C testable, it would need specific measurable features: instead of "professional," specify "matte black or gray exterior finish" (visual inspection), instead of "high-tech," specify "digital temperature display visible without opening" (functional check), or define specific features like "sealed gaskets visible" or "carrying handle included" (checklist verification). Establishing measurable requirements ensures objective design evaluation: every requirement should have a clear test method (temperature→thermometer, volume→graduated cylinder, cost→receipts), specific pass/fail criteria (2-6°C = pass, outside range = fail), and no room for subjective interpretation (meets number or doesn't—fact, not opinion).

Question 20

Hot lunch container design challenge: You need to design an insulated container that keeps 500 mL of soup hot from 7:00 AM until 12:00 PM (5 hours). The soup must stay at or above 60°C at lunchtime (safe eating temperature). The container must cost under $20, be no more than 15 cm tall so it fits in a backpack, be safe for students (the outside should not be hot enough to burn), and you may use only plastic, foam, and metal materials.

Which option lists the criteria (performance goals) for this design?

  1. Costs under $20, is no more than 15 cm tall, and uses only plastic/foam/metal
  2. Keeps soup at or above 60°C for 5 hours and holds 500 mL of soup (correct answer)
  3. Fits in a backpack and is made of metal so it is strong
  4. Keeps soup hot and is affordable and easy to carry
Explanation: This question tests understanding of how to establish design requirements by setting criteria (measurable performance goals the design must achieve) and constraints (limitations the design must work within). Design requirements have two components: (1) criteria—the performance goals that define success (what the design must accomplish: maintain ≥60°C temperature, work for 5 hours duration, hold 500 mL capacity, ensure safety with no burn risk from exterior), which are measurable targets that testing will verify (thermometer measures if temp ≥60°C met, timer measures if 5 hour duration met, pass/fail clear from measurements); and (2) constraints—the limitations that restrict how you can achieve the criteria (what you must work within: cost under $20 budget, size fits in backpack max 15 cm tall, materials limited to available foam/plastic/metal, safety requires food-safe materials), which bound the solution space preventing unlimited resources or unrealistic designs. For this hot lunch container: The criteria (performance goals) are: (1) maintain ≥60°C (temperature criterion: soup must stay at safe eating temperature, 60°C is minimum for hot food safety, testable with thermometer at end of 5 hours), (2) duration of 5 hours (time criterion: from 7 AM packing to noon eating, must keep hot this long, testable with timer), (3) capacity 500 mL (volume criterion: must hold a meal-sized portion, testable with measuring cup), and (4) safety (no burn hazard: exterior cool enough to touch even with hot soup inside, testable by touching exterior). The constraints (limitations) are: (1) cost under $20 (budget constraint: student/family can afford, eliminates expensive vacuum thermoses perhaps, testable by adding component costs), (2) size fits backpack (dimensions constraint: max 15 cm tall to fit with books, testable with ruler), and (3) materials available to foam, plastic, metal (resource constraint: can't use exotic materials not accessible, limits design choices). Choice B is correct because it correctly identifies criteria as measurable performance goals (temperature ≥60°C, duration 5 hours, capacity 500 mL). Choice A confuses criteria and constraints: lists cost, size, and materials which are all constraints (limitations), not performance goals; Choice C provides vague unmeasurable criteria like "strong" without specific values and mixes a constraint (fits in backpack) with an incomplete criterion; Choice D provides vague unmeasurable criteria like "keep hot" without specific temperature value (how hot? 40°C? 60°C? 80°C?—can't test objectively) and mixes constraints ("affordable") with vague goals. Establishing clear design requirements is the essential first step in engineering design process: (1) understand the problem (what needs to be kept hot? for how long? under what conditions?), (2) set criteria defining success (specific measurable goals: maintain ≥60°C, work for 5 hours, hold 500 mL—know exactly what "success" means), (3) establish constraints defining boundaries (realistic limits: budget $20, size 15 cm, available materials foam/plastic—work within practical boundaries), (4) make criteria testable (quantitative values allow objective pass/fail: thermometer reads 62°C at 5 hours = pass, reads 58°C = fail—no ambiguity), and (5) prioritize if needed (if cost and performance conflict, which matters more? for student lunch, maybe prioritize low cost; for medical transport, prioritize temperature control regardless of cost).