Thermos Engineering

Thermos Engineering

Middle School

​

Learning Objectives

• Define conduction, insulation, and vacuum and their roles in thermal energy transfer.

• Precisely define the criteria and constraints of a given design problem.

• Describe the engineering design process and how to evaluate competing design solutions.

• Explain how scientific principles are used to design and improve a thermos.

Key Vocabulary

​

Conduction

Conduction is the transfer of kinetic energy between particles that collide with one another.

​

Insulation

Insulation is any material used to reduce the rate of energy transfer between different objects.

​

Vacuum

A vacuum is a sealed and empty space that contains no particles, including the air.

​

Criteria

Criteria are the requirements that a particular design must meet in order to be considered successful.

​

Constraints

Constraints are the limitations or challenges that must be considered during the overall design process.

​

Energy Efficient

Being energy efficient means you are using less energy to successfully perform the exact same task.

Key Vocabulary

​

System

A system includes all the components and boundaries that make up a specific design problem.

​

Societal Impact

The effects that a new technology or solution has on people and the communities they live in.

​

Environmental Impact

The consequences or effects that a project has on the surrounding natural world and its ecosystems.

​

Evaluate

To carefully judge or assess different solutions by following a clear and systematic process of review.

What are Conduction and Insulation?

• Conduction transfers energy through direct particle collisions.

• Energy always flows from hotter to colder areas.

• Insulation uses materials to slow down this energy transfer.

Multiple Choice

What is conduction?

• The transfer of energy through direct particle collisions.

• The process of slowing down energy transfer.

• The flow of energy from colder to hotter areas.

• The creation of energy in a hot object.

Multiple Choice

What is the rule for how energy flows during conduction?

• From a hotter area to a colder area.

• From a colder area to a hotter area.

• Only between objects of the same temperature.

• Away from the colder area in all directions.

Multiple Choice

A person uses a thick cloth oven mitt to grab a hot pan from the oven. Which statement best explains why the mitt protects their hand?

• The material of the mitt slows down the transfer of heat from the pan to the hand.

• The mitt quickly cools down the handle of the hot pan.

• The mitt prevents the hand from producing its own heat.

• The mitt completely stops the flow of energy from the pan.

​

​

The Engineering Design Process

• Engineers use this structured process to design effective solutions to real-world problems.

• The first step is to define the problem and the needs of users.

• Then, engineers develop ideas, build prototypes, and test their performance.

• They use test results to improve the design until it meets all criteria.

​

Multiple Choice

What is the main purpose of the engineering design process?

• To design effective solutions to real-world problems.

• To conduct scientific experiments in a lab.

• To build prototypes that are inexpensive.

• To identify problems without trying to solve them.

Multiple Choice

What is the role of building prototypes and testing them within the engineering design process?

• They prove that the design is finished.

• They provide information to improve the design.

• They are the first step in defining the problem.

• They help the engineer choose a new problem.

Multiple Choice

An engineer designs a new backpack, but testing shows that the straps break when it's filled with heavy books. What is the most logical next step?

• Use the test results to modify the design and re-test it.

• Start over by defining a completely new problem.

• Build several more identical prototypes to see if they also fail.

• Conclude that the design is a failure and stop working.

​

​

Defining the Problem and System

• Engineers first identify the system and its major components.

• ​They also identify the people involved and what their needs are.

• Engineers consider both the positive and negative societal impacts of a solution.

• They also consider any positive or negative effects on the environment.

​

Multiple Choice

According to the engineering design process, what is the first step in defining a problem?

• To identify the system and its major components.

• To immediately start building a prototype.

• To calculate the final cost of the solution.

• To choose the materials for the final product.

Multiple Choice

Beyond identifying a system's components, what other key factors must engineers analyze when defining a problem?

• The needs of people and the effects on society and the environment.

• The color of the product and the marketing strategy.

• The time it will take to build and the tools required.

• The final price of the solution and how to sell it.

Multiple Choice

An engineer is planning a new factory in a small town. Which statement shows the most complete consideration of the problem?

• How the factory might create jobs but also produce waste that could affect the local river.

• Which specific machines the factory will use to build its products.

• How the factory can make the most amount of money in the first year.

• What the factory building will look like and what color it will be painted.

​

​

Defining Criteria and Constraints

Criteria

• Criteria are the measurable goals a solution must meet to be successful.

• They help to define what the final design is supposed to do.

• Engineers use them to compare different solutions to find the best one.

Constraints

• Constraints are the limitations or challenges that an engineer must work within.

• These can include limits on time, the budget, and available materials.

• They also include safety rules and negative effects on the environment.

Multiple Choice

What is the primary difference between criteria and constraints in an engineering project?

• Criteria are the project's goals, while constraints are its limitations.

• Criteria are the available materials, while constraints are the project's budget.

• Criteria are the safety rules, while constraints are the project's goals.

• Criteria are the project's limitations, while constraints are its measurable goals.

Multiple Choice

What is the main function of criteria when an engineer is evaluating different design solutions?

• To determine which solution best meets the measurable goals.

• To figure out which solution has the most limitations.

• To identify the safety rules that each solution must follow.

• To calculate the total budget required for each solution.

Multiple Choice

An engineer is tasked with designing a new drone that must be lightweight. They are also given a one-month time limit to complete the design. Which statement accurately classifies these two factors?

• The time limit is a constraint, while the need for it to be lightweight is a criterion.

• The time limit is a criterion, while the need for it to be lightweight is a constraint.

• Both the time limit and the lightweight requirement are criteria.

• Both the time limit and the lightweight requirement are constraints.

​

​

Evaluating Competing Design Solutions

• Engineers evaluate multiple solutions to find the most effective one.

• ​They compare each solution against the project's criteria and constraints.

• A decision matrix is a tool used to organize and rate each solution.

• This helps engineers justify their choice for the best possible design solution.

​

Multiple Choice

What is the primary goal when engineers evaluate competing design solutions?

• To find the most effective solution for a problem

• To make a project take longer to complete

• To choose the design that is the most expensive

• To prove that their first idea was the best one

Multiple Choice

How does using a decision matrix help engineers compare different solutions?

• It helps them organize and rate the solutions based on project criteria

• It is used to create the first drawing of a design

• It lists the names of all the engineers on a project

• It is a tool for building the final prototype

Multiple Choice

An engineer has used a decision matrix to rate three different solutions for a new bridge. What is the most logical conclusion this process supports?

• It allows them to use the ratings as evidence to justify their final choice

• It proves that all of the design solutions are equally effective

• It eliminates the need to consider the project's constraints

• It shows them how to build all of the solutions at the same time

​

​

How a Thermos Works

• A thermos has a double-wall design with a space in between.

• The air between the walls is removed to create a vacuum.

• A vacuum is a space that contains almost no particles.

• The vacuum stops heat transfer by conduction, keeping the contents hot or cold.

​

Multiple Choice

What is the primary function of the vacuum in a thermos?

• To create a space for extra air.

• To make the thermos walls stronger.

• To stop heat transfer by conduction.

• To hold more liquid inside.

Multiple Choice

Why is a vacuum effective at preventing heat transfer by conduction?

• A vacuum contains almost no particles, which are needed for conduction.

• The space between the walls traps air, which is a good insulator.

• The double-wall design makes the thermos heavier, slowing heat loss.

• Removing the air makes the inner wall reflective to heat.

Multiple Choice

What would most likely happen if the seal on a thermos broke, allowing air to fill the space between the double walls?

• The thermos would keep the drink hot for a longer period.

• Heat would transfer through the air particles, and the drink would cool down faster.

• The pressure from the air would crush the inner wall.

• There would be no change in the thermos's performance.

Insulation in Buildings and Windows

• Insulation in walls reduces the transfer of heat by conduction.

• This makes buildings more energy-efficient, saving money and resources.

• Double-paned windows use trapped gas to provide superior insulation.

Multiple Choice

What is the primary function of insulation in the walls of a building?

• To reduce the transfer of heat.

• To increase the strength of the walls.

• To make a building look more modern.

• To generate electricity for the building.

Multiple Choice

What is the main benefit of reducing heat transfer in a building by using insulation?

• It makes the building more energy-efficient.

• It prevents windows from breaking easily.

• It helps the building absorb more heat from the sun.

• It reduces the need for electrical wiring.

Multiple Choice

Which statement best explains why a double-paned window provides superior insulation?

• The two panes of glass block more light from entering.

• The trapped gas between the glass panes reduces heat transfer.

• The extra layer of glass makes the window harder to open.

• The gas heats up, which helps to warm the building.

​

Common Misconceptions

Misconception	Correction
Insulation completely stops all energy transfer.	Insulation only slows down the rate of energy transfer.
A vacuum 'sucks' heat away.	A vacuum is an empty space that prevents energy transfer through conduction.
Engineering is a simple, linear process.	The engineering design process is iterative, repeating steps to improve designs.

​

Summary

• Energy transfers via conduction, and insulation, like the vacuum in a thermos, slows it.

• The engineering design process is a cycle of defining, developing, and testing solutions.

• The process starts by defining the problem’s criteria (goals) and constraints (limitations).

• Solutions are evaluated on criteria, constraints, and societal and environmental impacts.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

• 1

• 2

• 3

• 4