Year 9 Science · Unit 3 · Lesson 23
Apply Worksheet
Learning Goals
Calculate classroom energy use
Scenario
A typical classroom at Riverside Secondary College, NSW, contains: 30 LED lights (10 W each), 1 air conditioner (2400 W), 5 computers (150 W each), 1 interactive projector (300 W). All appliances run for 6 hours per school day across 200 school days per year. Electricity costs $0.30 per kWh.
Key formula: Energy (Wh) = Power (W) × Time (h) | 1 kWh = 1000 Wh
| Appliance | Power (W) | Annual energy (kWh) | Annual cost ($) |
|---|---|---|---|
| 30 LED lights | |||
| Air conditioner | 2400 W | ||
| 5 computers | |||
| Interactive projector | 300 W | ||
| TOTAL |
Which single appliance dominates the classroom's energy use? What percentage of total energy does it use?
Design a depth study investigation
Design a depth study to investigate energy use at your school. Fill in each box below.
Research question: Write a testable question about energy use at school. (Example format: "Does ______ affect ______ ?") Must be specific and measurable.
Hypothesis: Write an if-then-because prediction. "If ______, then ______, because ______."
Controlled variables: List THREE variables you would keep the same to ensure a fair test.
Data collection: How would you collect your data? What tools or instruments would you use, and how often would you measure?
Displaying results: What type of graph would you use to display your results, and why is it the most appropriate choice?
Wrap Up
In one sentence, what was the main idea of this lesson?