Lesson 7 of 10 · Energy
Lesson⭐ 30 XP⚡ Spark LabSankey Diagrams
Sankey Diagrams.
🎯 Your mission
Understand the idea. Then look for it everywhere.
⚡ The twist
Speed isn't the same as force. Don't mix them up.
Mind = Blown
🔥 A bolt of lightning is 5 times hotter than the surface of the sun.
Make a hypothesis first
Guess: where does the energy go?
What You'll Learn
A Sankey diagram draws energy flow as arrows whose widths are proportional to the energy carried. Input enters from the left, useful output continues right, and wasted energy branches downwards. The widths must always add up.
Key Words
Tap a word to see its definition.
Steps
Read the explanation above and note the two key terms before you start.
Draw a scaled Sankey diagram for a filament lamp taking 100 J and delivering 5 J of light, then one for an LED lamp taking 100 J and delivering 40 J. Use 1 mm per joule and check both diagrams balance.
Record what actually happened, including anything that did not match what you expected.
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Check Your Understanding
Question 1
1 of 2In a Sankey diagram, arrow width represents:
Where you see this in real life
You use this every time you flip a light switch, ride a bike, or kick a ball.
Stretch Challenge
Try this in real life this week.
Time how long a small ball rolls down something, then change the slope and try again.
For the dinner table
“Show me something at home that uses this kind of energy.”
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Sankey Diagrams
Understand the idea. Then look for it everywhere.
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