Year 9 Science · Unit 3 · Lesson 2
Apply Worksheet
Learning Goals
Order the steps
Number the events from 1 to 7 to show the correct order of energy transformations in a hydroelectric dam. Event 1 = what happens first.
| Order | Event |
|---|---|
| The generator converts the kinetic energy of the spinning turbine into electrical energy. | |
| Some electrical energy is lost as heat in the transmission wires as it travels to homes. | |
| Water stored at height in a dam reservoir possesses large amounts of gravitational potential energy. | |
| The electrical energy is distributed through the National Electricity Market to homes across the region. | |
| As water falls through penstocks (pipes), its gravitational potential energy converts to kinetic energy. | |
| The fast-moving water strikes turbine blades, causing them to spin, kinetic energy transferred from water to turbine. | |
| Electrical energy powers appliances in homes, transforming to light, sound, heat, or kinetic energy. |
Compare two
Complete the table to compare an open system and a closed system in the context of energy conservation.
| Feature | Open system | Closed system |
|---|---|---|
| Definition | ||
| Can energy enter or leave? | ||
| Does total energy stay constant? | ||
| Real-world example | ||
| Does conservation of energy still hold? |
1. A hydroelectric dam converts gravitational potential energy into electrical energy. Using the law of conservation of energy, explain what happens to energy that does not become electrical energy, and why this does not break the law.
2. A student says: "Our classroom is a closed system, we can track all the energy." Evaluate this claim. Is the classroom a closed system? Justify your answer with TWO reasons.
Wrap Up
In one sentence, what was the main idea of this lesson?