Title Post date
What do I (we) do about my (our) carbon footprint? Keywords: Carbon footprint, reduction

A very frequent question asked by students after learning about climate change is "But what can I (we) do about it?". Here are some ideas, all of which have benefits in addition to reducing greenhouse gases, and so are worth considering even if you reject the idea of anthropogenic global warming completely.

Here is a set of suggestions for science students who wish to take action to reduce their own and their family's or community's carbon footprint. Most of the ideas are about education and attitude. We also list three achievable ways of reducing your annual emissions by least a tonne of carbon dioxide.

5 years 35 weeks ago
Solar Powered Airplanes Keywords: airplanes, estimation, solar cells, solar energy

If we were to coat a Boeing 747 jumbo jet with solar panels, is it possible to fly it using only the energy generated by these solar panels?

This module introduces the concept of estimation, both in the sense of rounding extremely precise numbers off to remove excessive significant figures, and simplifying a complex process (the flight of a 747) to a simpler one, by evaluating the possibility of powering a 747 with solar panels.

7 years 8 weeks ago
Pitot Tubes Keywords: air speed, Bernoulli's equation, fluid speed, fluids, Pitot tubes

How can wasps endanger a commercial airline flight?

This article explains how a Pitot tube is used to measure speed of a fluid and is applied to measure the air speed of aircraft. Bernoulli's equation forms the basic principle of fluid speed measurements using Pitot tubes.

3 years 4 weeks ago
How much do grade 10 students know about our energy consumption? Keywords:

Do students understand how similar we are to the machines we make?

The human body and the internal combustion engine are quite similar in that they are both heat engines requiring chemical energy to run.
By placing a question related to this notion on a national science contest, we attempted to discover what Grade 10 students think.

5 years 16 weeks ago
How big was the aerodynamic force on Felix Baumgartner at 1342 km/h? (Or on Alan Eustace at 1321 km/h?) Keywords: aerodynamics, drag, felix baumgartner, free fall

Did you watch Felix Baumgartner jump out of a balloon gondola at an altitude of 39 km? Here's a question for your physics students, or even your physics teacher! How big was the drag force on Felix Baumgartner at his maximum speed of 1342 km/h? Pretty enormous, right? Wrong.

Knowing next to nothing about how aerodynamic drag varies as one hits the sound barrier, there is very simple way to assess the aerodynamic drag on a falling object at its maximum speed. Even at 1432 km/h. In fact the maximum aerodynamic drag occurs afterwards when the falling object is slowing down in the denser lower atmosphere. To asses how big the force was on Felix Baumgartner, we create a simple mathematical model of his fall.

4 years 35 weeks ago
Food, Energy and the Environment Keywords: energy balance, Food, greenhouse gases

How do we feed nine billion people without destroying our environment?

The primary function of food is to provide our bodies with energy. Most of this energy comes ultimately from oil, with a little sunlight added, and its production is an energy-inefficient process.

5 years 19 weeks ago
Flying Keywords: aircraft, birds, energy, flight, transport cost

It takes energy to fly. How much?

We examine how much energy it takes to fly from A to B, whether by bird, model glider, small plane or 747.

7 years 1 week ago
Energy Use in Cars 6: Gasoline Cars vs. Bicycles Keywords: air resistance, bicycle, energy use in cars, fuel economy, rolling resistance, vehicle transportation

When does a car have the same fuel efficiency as a bicycle?

A comparison of the energy cost of transportation between cars and bicycles.

7 years 9 weeks ago
Energy Use in Cars 5: Gasoline Cars vs. Electric Cars Keywords: electric cars, energy use in cars, fuel economy, vehicle transportation

How do the greenhouse gas emissions of electric and gasoline cars compare?

A comparison of the energy cost and greenhouse gas emissions of gasoline and electric cars.


7 years 9 weeks ago
Energy Use in Cars 4: Regenerative Braking Systems Keywords: energy use in cars, fuel economy, regenerative braking, vehicle transportation

What single system could be added to a gasoline car to improve its city driving fuel economy by 30-40%?

A calculation of the fuel consumption due to stop-and-go driving, for the purposes of estimating potential savings from a regenerative braking system.

7 years 9 weeks ago
Energy Use in Cars 3: Rolling Resistance Keywords: energy use in cars, fuel economy, rolling resistance, vehicle transportation

Why does Natural Resources Canada recommend keeping your tires inflated to conserve gasoline?

A rough calculation of rolling resistance in cars explores the impact of having underinflated tires.

7 years 9 weeks ago
Energy Use in Cars 2: Constant Speed Cruising Keywords: air resistance, drag, efficiency, energy use in cars, fuel economy, vehicle transportation

If a body in motion tends to stay in motion, why do we need to burn gas to travel at highway speeds?

Why do we need to burn gas to keep travelling at the same speed? The basic answer is "because if we didn't, eventually the car would stop." In everyday life, there is always friction and air resistance that opposes any motion, and if you leave a moving object alone, this friction and drag will eventually cause it to stop. This lecture looks at how this drag impacts a car.

7 years 9 weeks ago
Energy Use in Cars 1: Stop-and-Go Driving Keywords: efficiency, energy use in cars, fuel economy, kinetic energy, vehicle transportation

When does cycling cost more in fuel than driving?

People recommend commuting by bicycle rather than by car to save energy. However sometimes when a cyclist pushes the button to make a traffic light change, it means that a bus full of people has to stop. When a cyclist makes the bus stop like this, is the extra fuel it has to burn to get back up to speed MORE than the fuel saved by choosing to commute by bicycle rather than car?

7 years 9 weeks ago
Energy Cost of Transport Keywords: energy, transport

How much energy does it take to move a person or a tonne of freight from A to B?

We compare how much energy it takes to move something from A to B using a variety of means: road, rail, water, air, and if that something is a human, walking and bicycling.

7 years 1 week ago
Energy and Power Keywords: definition, energy, types, useage

What is energy? Why is it such a useful concept? How does it relate to power?

Energy is the capacity to do work (both are measured in Joules). Power is the rate at which energy is transformed from one state to another, often from a stored state into work (a Joule of energy transformed per second is a Watt of power). Subsistence living requires about 200 W per person. Western living requires about 10 kW per person. Humankind currently uses about 12.5 TW of power, most from fossil fuels. Ten billion people living a western lifestyle (the not-impossible goal of many futurists) would require 100 TW of power.

5 years 49 weeks ago
Cycling and Showering Keywords: cycling, energy use, heat capacity, showering

Are cycle commuters, who take an extra shower, doing more damage to the environment than those who commute by car?

A recent letter to the Vancouver Sun claimed that commuting by bicycle was worse for the environment than commuting by car. The reason given was that if a cycle-commuter takes an extra shower at work (because cycling makes you sweaty), that burns the energy equivalent of a litre of gasoline, which is more than a car would burn on an average commute. Fact or rubbish?

7 years 10 weeks ago
Comparing Energy and Heat Units Keywords: BTU, cost, energy, greenhouse gases, oil barrel, quad, R-value, thermal conductivity, thermal resistance, unit conversion, Watts

How do I compare heat and energy values given in different units?

A look at how to compare the costs of natural gas, gasoline and electricity and how to convert between various heat units including R-values, U-values, BTU/h, W and more.

7 years 2 weeks ago
Commuting by car or cycle - which is better? Keywords: bicycle, Carbon footprint, consumption, cycling, energy, Food, spreadsheets

It's not actually that clear...

We set out to find how much of a change it would make environmentally if one cycled instead of drove to work and then further expanded our findings to include the variables of diet composition and material goods ownership.

5 years 19 weeks ago
Bottle Rockets Keywords: air, bottle, force, fuel, pressure, rocket, thrust, water

Bottle Rockets - a future mode of transport?

This article explores the physics behind bottle rockets and how they work. It also discusses whether or not bottle rockets would be a viable means of transport.

6 years 50 weeks ago
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