Lesson 5 of 7 · Electricity
Experiment⭐ 30 XP⚡ Spark LabElectrical Power and Energy Cost
Electricity.
🎯 Your mission
Set it up. Test it. Be amazed.
⚡ 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
Electrical power is P = VI, and also I²R. Energy used is power times time, and household bills are charged in kilowatt-hours: one kilowatt running for one hour. A 2 kW heater run for three hours uses 6 kWh.
Key Words
Tap a word to see its definition.
Materials Needed
- appliance rating plates
- electricity meter readings
- calculator
Safety First
- Read rating plates only — never open an appliance or a meter cabinet.
Steps
Read the explanation above and note the two key terms before you start.
List six household appliances with their power ratings and estimate daily running hours. Calculate kWh per week for each and rank them, then compare your total with a real meter reading taken a week apart.
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 2A 2 kW heater runs for 3 hours. Energy used is:
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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Electrical Power and Energy Cost
Set it up. Test it. Be amazed.
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