Chapter 3 · ICSE Class 7 Physics (Selina Concise)

Energy

Explore different forms of energy, the law of conservation of energy, and how energy transforms from one form to another.

⚡ Chapter 3

Energy transforming from potential energy to kinetic energy as a ball falls A ball at the top of a height has potential energy, and as it falls, that potential energy transforms into kinetic energy, the energy of motion Potential Energy (at rest, height) Kinetic Energy (falling, moving)
3.1

Forms of Energy

Energy exists in many forms: kinetic (motion), potential (stored), heat, light, sound, chemical, and electrical energy.

1

What form of energy does a stretched rubber band have?

Potential energy (elastic potential energy)

2

What form of energy does a moving car have?

Kinetic energy

3.2

Energy Transformation and Conservation

Energy cannot be created or destroyed, only transformed from one form to another (law of conservation of energy).

1

What energy transformation happens in a torch/flashlight?

Chemical energy (battery) transforms into electrical energy, then into light energy

2

What energy transformation happens when a ball is dropped?

Potential energy transforms into kinetic energy as it falls

Practice

Exercises

1. What form of energy does food provide to our bodies?

2. What energy transformation occurs in a solar panel?

3. What is the law of conservation of energy?

4. What form of energy does a compressed spring have?

5. What energy transformation happens in a burning candle?

Next chapter — Light Energy 💡 →