Unit D Lesson 7: Metaphors for Electricity
Completion requirements
Unit D Lesson 7: Metaphors for Electricity
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Learning Targets |
Big Question: How does a waterfall help to explain the behaviour of electricity?
You have probably heard that electricity "flows". Thinking about the flow of electricity as being similar to the flow of water can help to make sense of circuits.
You have probably heard that electricity "flows". Thinking about the flow of electricity as being similar to the flow of water can help to make sense of circuits.
At the end of this inquiry, you should be able to answer the following questions:
- What are the relationships among voltage, current, and resistance ?
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How are
voltage, current, and resistance
related to a waterfall model?
Pages 304 and 305 in your textbook will help you answer these questions about metaphors for electricity.
Introduction
Figure 1– Water is pumped to the top of the waterslide, then flows downhill.
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How is an electric circuit like a waterpark?
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What do children on a waterslide represent if we compared them to an electric circuit?
- What part of a circuit would the waterslide represent?
Metaphors and analogies can help us to understand difficult concepts. The analogy of a waterfall may help you understand the components of electric circuits. The water flowing in a waterfall is similar to the current flowing in a circuit. Waterfalls have trees and rocks in the way of the water, and circuits have resistors or loads that slow the flow of electricity. What makes the water in the waterfall move in the first place?
Water falls due to the gravitational potential energy it has by being higher than the level immediately beyond. (Yes, water flows downhill – and electricity takes the path of least resistance, too!) When the water falls, the potential energy slowly turns into kinetic energy. This is similar to the potential energy in a battery. The battery has chemical potential energy. When the chemicals in a battery mix, they release energy in the form of electricity. Both the waterfall and battery have potential energy – but different types.
Watch
Is an electrical wire similar to a garden hose? Use the videos "An Analogy - water circuits for electric circuits" and "Analogy to Understand Electric Currents" to help see this comparison.