Lesson 1 Energy Flow in Technological Systems
Development of the Concept of Energy
The presence of energy in various forms was observed and studied by scientists long before they could explain fully what they were observing.
©Wikimedia Commons
C1.12 Benjamin Thompson, Count Rumford
C1.12 Benjamin Thompson, Count Rumford
Sir Benjamin Thompson was an American-born physicist and inventor who later became Count Rumford. In the early 1800s, Rumford became the minister of war in Bavaria and supervised workers that were boring brass cylinders to make cannons. “Boring” is
the process of making the hole in the cannon the correct diameter and is used to achieve the best possible accuracy of the diameter.
Due to the
friction created when boring the brass to make the cannons, huge amounts of heat were created. He showed that he could boil a kettle of water simply from the heat created by the
friction. Rumford was the first person to realize and propose that the motion of the workers (mechanical energy) and heat were related.
C1.13 Antique cannon
©Wikimedia Commons
C1.14 James Prescott Joule
C1.14 James Prescott Joule
By the middle of the 1840s, an English physicist by the name of James Prescott Joule was performing experiments that investigated the relationship between potential energy and heat, as well as experiments that connected kinetic energy and heat.
Joule wanted to see how motion was converted into heat. To do this, he held a weight at a specific height, giving it potential energy, and let it drop. The weights are connected to paddles within a container of water. As the weight falls, the
paddles within the container move, stirring the water and heating it. Joule made the connection that the more potential energy the weight had (the higher it was held), the more energy that was transferred to the stirring of the water.
Joule’s findings later led to the law of conservation of energy, which led to the first law of thermodynamics. The SI unit of energy, the joule, is named after James Joule.
Joule’s findings later led to the law of conservation of energy, which led to the first law of thermodynamics. The SI unit of energy, the joule, is named after James Joule.
C1.16 Inukshuk against a Canadian sunset
It is important to also look in Canada’s past to appreciate the contributions to the understanding and appreciation of the various forms of natural energy. For thousands of years, the First Nations, Métis, and Inuit have inhabited Canada and lived
with the land. They have followed traditional lifestyles of hunting and fishing for as long as possible.
Almost everything produced today depends on natural resources. Petroleum products supply everything from plastics to fertilizers to tires. Buildings are heated by wood, coal, oil, or natural gas. Electrical energy comes from burning fossil fuels, such as coal, or from hydroelectric generation.
Demand for more energy for new consumer goods and technological advances places a huge strain on the natural world. Also, there are rising expectations and an increasing population in Canada. There is always a search for more energy and resources, so industries look in even the most inaccessible areas. These are often the homelands of Indigenous peoples, which result in the displacement of Indigenous peoples from ancestral lands.
Almost everything produced today depends on natural resources. Petroleum products supply everything from plastics to fertilizers to tires. Buildings are heated by wood, coal, oil, or natural gas. Electrical energy comes from burning fossil fuels, such as coal, or from hydroelectric generation.
Demand for more energy for new consumer goods and technological advances places a huge strain on the natural world. Also, there are rising expectations and an increasing population in Canada. There is always a search for more energy and resources, so industries look in even the most inaccessible areas. These are often the homelands of Indigenous peoples, which result in the displacement of Indigenous peoples from ancestral lands.
Read This
Please read the sections titled “Heat and Mechanical Energy” and “Joule’s Experiments” on pages 169 to 170 in your Science 10 textbook. Make sure you take notes on your readings to study from later. You should focus on the contributions of Rumford
and Joule and how the concept of energy was developed from their observations of heat and mechanical devices. Remember, if you have any questions or do not understand something, ask your teacher!
Practice Questions
Complete the following practice questions to check your understanding of the concept you just learned about. Make sure you write complete answers to the practice questions in your notes. After you have checked your answers, make corrections to your
responses (where necessary) to study from.
- What was the main contribution that Sir Benjamin Thompson (Count Rumford) made to the understanding of what energy is?
Thompson (Rumford) was the first scientist to make the connection between motion due to friction and heat being produced as a result of the mechanical energy.
- What was the main contribution that James Joule made to the understanding of what energy is?
Joule made the connection between the potential energy a weight had due to its position above Earth and the amount of heat energy that the potential energy could be converted to.
- What is the main contribution that the Indigenous people of Canada made to the understanding of what energy is?
The Indigenous people of Canada noted the importance of the natural energy that is found on Earth and the importance of preserving that energy and not overusing it at the expense of the people that live on the land.