Understanding Sankey Diagrams

The video introduces Sankey diagrams, which visually represent energy flow in systems, showing input, useful output, and energy loss. It provides step-by-step instructions for drawing these diagrams, using examples like a car's energy conversion and a coal power plant. The video also discusses calculating system efficiency using Sankey diagrams and highlights their application in complex scenarios, such as national energy consumption.

What is the primary purpose of a Sankey diagram?

• To calculate the speed of a vehicle

• To measure the temperature of a system

• To show the flow of energy within a system

• To determine the color of an object

What is the first step in drawing a Sankey diagram?

• Drawing arrows for energy flow

• Deciding how much energy each grid square represents

• Labeling the type of energy

• Calculating the efficiency

How is the useful energy represented in a Sankey diagram?

• By a vertical line

• By a horizontal arrow pointing right

• By a circle

• By a diagonal line

In the car example, what type of energy is considered useful?

• Chemical energy

• Potential energy

• Kinetic energy

• Thermal energy

What does a curving arrow in a Sankey diagram typically represent?

• Useful energy

• Potential energy

• Lost energy

• Total energy

In a complex scenario like a coal power plant, what does the Sankey diagram help illustrate?

• The temperature of water

• The proportion of energy lost at each stage

• The speed of turbines

• The color of coal

How many boxes high is the rectangle for 160 Joules in a Sankey diagram if each box represents 20 Joules?

• 4 boxes

• 6 boxes

• 10 boxes

• 8 boxes

What is the efficiency of a system if there are two boxes of useful energy and five boxes of total energy?

• 40%

• 60%

• 50%

• 20%

What can Sankey diagrams be used to calculate besides energy flow?

• System color

• System efficiency

• System speed

• System temperature

What does the ultimate Sankey diagram for the United States show?

• US climate change data

• US economic growth

• US population growth

• Total US energy consumption