C. Matter and Energy · Fluids

Technologies That Use Fluids: Weighing the Impacts

C1.1 A1.1 A1.5 A3.1 A3.2 A3.3About 55 minutes

Learning goals

I can identify technologies that depend on the properties of fluids.
I can assess the environmental, social and economic impacts of a fluid technology.
I can describe contributions of First Nations and Inuit to technologies that use fluids.
I can use a research process to gather information from reliable sources.

Words to know

technology
A tool, device, system or process that people design to solve a problem or meet a need.

innovation
A new idea, device or way of doing something, or an improvement to an old one.

environmental impact
An effect on air, water, land, plants or animals.

social impact
An effect on people's health, safety, communities, culture or way of life.

economic impact
An effect on money, jobs, costs and businesses.

refrigerant
A fluid used in fridges, freezers, air conditioners and heat pumps that carries heat as it evaporates and condenses.

Fluids power our lives

Think about your morning. Water comes out of the tap because of pressure in the pipes. Your fridge kept your milk cold using a fluid called a refrigerant. The electricity for your toast might have come from flowing water at a generating station. The bus you took may have air brakes and kneeling air suspension.

Every one of these is a technology built on the properties of fluids. Every one also has impacts, good and bad. Today you'll learn to weigh them.

A concrete dam and generating station across a wide river, with white water rushing out below and forest on both banks. — A hydroelectric generating station uses flowing water to make electricity. Think about its environmental, social and economic impacts, both positive and negative. AI-generated image

How to assess impacts

A fair assessment looks at three kinds of impact, both positive (+) and negative (−):

Environmental: air, water, land, plants, animals, climate.
Social: health, safety, communities, culture, ways of life, who benefits and who bears the costs.
Economic: costs to build and run, jobs, prices, businesses.

Ask: Who is affected? Where: locally or globally? When: now, or for generations? Then make a judgment and back it up with evidence.

Worked example

Let's assess a hydroelectric generating station

Hydroelectric stations use the flow of water through turbines to make electricity. Ontario has many, including large stations at Niagara Falls. Assess the impacts of building a new dam and reservoir.

Step 1. What property of fluids does it use? Water flowing from higher to lower pressure (from the top of the dam down through the turbines) pushes the turbine blades.
Step 2. Environmental. (+) It doesn't burn fuel, so it gives off very little greenhouse gas while running. (−) Building a reservoir floods land and changes rivers. Dams can block fish from swimming upstream to spawn (fish ladders help). Flooding soil can release mercury into the water, where it can build up in fish.
Step 3. Social. (+) Reliable electricity for homes, hospitals and schools. (−) Some dams in Canada flooded the lands of First Nations communities, harming places for hunting, fishing, gathering and ceremony, and some communities had to move. Today, some First Nations co-own new hydroelectric projects and share in the benefits.
Step 4. Economic. (+) Once built, it runs for many decades with low operating costs and creates jobs. (−) Dams are very expensive to build.
Step 5. Judge. Write a balanced conclusion that weighs the evidence and says what would make the project better.

Sample judgment: hydroelectricity provides clean, reliable power for a long time, but large new dams have serious environmental and social costs. A project is more acceptable when the affected First Nations are full partners in planning and benefits, when fish passage and mercury are managed, and when smaller or run-of-river designs are considered.

A hydroelectric station (simplified, not to scale). Water flows from the high reservoir, through the dam, and spins a turbine, which turns a generator (G) to make electricity.

Technology	Fluid property it uses	One possible + impact	One possible − impact
Pipelines (oil, natural gas, water)	flow from high to low pressure; pumps	move huge amounts cheaply, with fewer trucks on roads	leaks and spills can harm land, water and communities
Hydraulic excavators and loaders	Pascal's law; liquids are incompressible	do heavy work quickly and safely; create skilled jobs	burn fuel; hydraulic oil leaks can pollute soil
Fridges, freezers and heat pumps	refrigerant absorbs heat as it evaporates and gives it off as it condenses	keep food safe; heat pumps can heat homes efficiently with electricity	some refrigerants harm the ozone layer or are strong greenhouse gases if they leak
Air brakes and kneeling buses	air is compressible	safer heavy vehicles; easier boarding for people who use wheelchairs	compressors use energy; noise
Life jackets and personal flotation devices	buoyancy: low average density	save lives on lakes and rivers	worn-out foam and plastic add to waste

Some technologies based on the properties of fluids, with sample impacts.

A lesson from the ozone layer

In the 1970s and 1980s, scientists found that CFCs, refrigerants used in fridges and spray cans, were damaging the ozone layer that shields Earth from harmful ultraviolet light. In 1987, countries signed the Montreal Protocol to phase CFCs out. It shows that a fluid technology's impacts may not be known until years later, and that countries can work together to fix them.

From warning to action. Countries agreed on the Montreal Protocol only 13 years after scientists first warned about CFCs, and the ozone layer is now slowly recovering.

Contributions of Indigenous peoples

First Nations and Inuit have designed technologies that use the properties of fluids for thousands of years, and these designs are still used around the world.

The qajaq (kayak): Inuit designed the qajaq, traditionally a light frame of driftwood or bone covered with sealskin. Its shape is buoyant, fast and stable enough for hunting on cold Arctic waters. Kayaks used around the world today come from Inuit designs.
The avataq: an Inuit sealskin float filled with air and tied to a harpoon line. Its buoyancy stops a harpooned animal from sinking and tires it out.
The birchbark canoe: many First Nations, such as the Anishinaabe, build canoes from birchbark over a cedar frame. The canoe is light, floats high in the water, and can be carried over portages between lakes and rivers. Builders today still make birchbark canoes and teach young people the skills.

These technologies show deep knowledge of density, buoyancy and the flow of water, developed through careful observation and passed on through generations.

Just for fun

Why is the refrigerant so good at handling stress?

It always keeps its cool. (Well, it actually carries the heat away, which is even cooler.)

Hands-on activity

Research and assess a fluid technology

Part 1: fluid technology hunt at home. List every technology in your home that depends on a fluid property. Hints: taps and pipes, the toilet, the water heater, the furnace and its fan, the fridge, a bike pump, a spray bottle, a car or bike's brakes. For each, write the fluid and the property it uses.

Part 2: research. Choose one technology from this lesson or your list (for example: heat pumps, hydraulic excavators, the Inuit qajaq, pipelines, snowmaking at ski hills, or water towers).

Ask a question: "What are the environmental, social and economic impacts of ___?"
Find at least three reliable sources. Good sources include government websites (sites ending in .gc.ca or ontario.ca), museums, universities, and organizations of the people involved (for example, Inuit or First Nations organizations). Ask a grown-up to help you search safely.
Check each source: Who wrote it? When? Could they be biased (for example, a company selling the product)?
Organize your notes in a table with + and − for each type of impact.
Communicate: make a one-page fact sheet, infographic or short slide talk for your family. End with your judgment and one suggestion to reduce the negative impacts.

What to look for: a strong assessment has evidence for both sides, names who is affected, cites its sources, and ends with a clear, reasoned judgment.

Safety: use the internet with a grown-up's permission and don't share personal information.

Your turn

Name the three kinds of impact you should consider when assessing a technology.

What property of fluids does a hydroelectric station use?

Give one positive and one negative environmental impact of a large hydroelectric dam.

What fluid property does a life jacket use?

Describe one Inuit technology that uses the properties of fluids.

Why was the Montreal Protocol signed?

More practice: warm-up

What fluid carries heat in a fridge or heat pump?

Is "creates jobs" an environmental, social or economic impact?

Which First Nations technology can be carried over portages?

Name a technology that uses compressed air.

Name one reliable kind of source for research.

More practice: on your own

Give one social impact (positive or negative) of oil pipelines.

Why should you check whether a source might be biased?

How does the birchbark canoe show an understanding of buoyancy?

Heat pumps can heat homes using electricity instead of burning fuel. Name one benefit and one concern.

What does the Montreal Protocol teach us about new technologies?

Challenge

A town is choosing between a new water tower and electric pumps to keep water pressure up. Name the fluid property a water tower uses, and give one economic and one social factor the town should consider.

Explain why involving First Nations as partners matters when planning a hydroelectric project on their traditional territory.

Choose any technology from this lesson. Write a balanced three-sentence judgment about it (one positive, one negative, one recommendation).

Check your understanding

Quiz

Which of these is a social impact of a new dam?

A refrigerant is a fluid that...

The Montreal Protocol (1987) was an agreement to...

Which technology was designed by Inuit?

Which is an economic impact of a hydraulic excavator?

Which source is most likely to be reliable and balanced?

For parents and teachers

Big idea (C1.1): students assess the environmental, social and economic impacts of technologies based on fluid properties: hydroelectricity, pipelines, hydraulic machinery, refrigeration and heat pumps, air brakes, flotation. A3.3 is addressed through Inuit and First Nations technologies (qajaq, avataq, birchbark canoe). The research activity follows a research process (A1.1) and communication (A1.5); the trades and real-world problems connect to A3.1 and A3.2.

How to help: walk through your home naming fluid technologies together. When your child researches, help them judge sources: who wrote it, when, and why.

Common difficulties:

One-sided answers. Ask: "Who might disagree? What's a negative?"
Mixing up social and economic impacts. Money and jobs = economic; health, safety and ways of life = social.
Talking about Indigenous peoples only in the past tense. First Nations and Inuit communities are living communities today; many still build canoes and kayaks and co-own energy projects.

Safety: supervise internet research.